| | | | (+5,
-5) | | Cigarette Air-Bags | | Science: Health: Smoking |
| | | | (0) | | Cigarette cashback | | Science: Health: Smoking: Deterrent |
| | | | (+1,
-1) | | Cigarette Paper | | Product: Cigarette: Paper |
| | | | (0) | | cigarette paper - foolproof | | Product: Cigarette: Paper |
| | | | (+3,
-3) | | Cigarette risk | | Science: Health: Smoking |
| | | | (0) | | cigarettes | | Product: Cigarette: Length |
| | | | (0) | | Cinch tool | | Product: Tool: Sliding |
| | | | (0) | | Cinema for the Blind | | Culture: Movie Theatre: Captions |
| | | | (0) | | Circuit breaker with current transmitter | | Home: Electricity |
| | | | (0) | | circular airfoil creating suction | | Vehicle: Car: Aerodynamics |
| | | | (+1,
-1) | | Circular Rolling Door | | Home: Door |
| | | | (0) | | Cistern mounted toilet brush | | Home: Toilet: Hygiene |
| | | | (0) | | c.it.again.com | | Computer: Web: Searching |
| | | | (+1,
-1) | | Citrus Cycle | | Vehicle: Car: Engine: Electric |
| | | | (+1,
-1) | | CIty Aircon | | Public: City: Climate |
| | | | (0) | | City as Canvas | | Computer: Display: Large Area |
| | | | (0) | | City Labyrinth | | Culture: Game: Maze |
| | | | (+2,
-2) | | city that never sleeps | | Other: Simulation |
| | | | (0) | | Cityname Light Beacons | | Science: Light |
| | | | (+2,
-2) | | Civvie-Street Action Man | | Product: Toy: Doll |
| | | | (0) | | Claims Accountability Fines | | Business: Financial |
| | | | (+1,
-1) | | clam backed dollar | | Public: Currency: Medium |
| | | | (0) | | Clamper Catapult | | Sport: Projectile |
| | | | (0) | | Clandestine Remote Control Cat Bomb | | Product: Weapon: Bomb: Delivery |
| | | | (0) | | Clap Trak | | Product: Remote: Location |
| | | | (0) | | clappApp - clap community app | | Public: Communication |
| | | | (+2,
-2) | | Clapping Lamps | | Product: Light: Color |
| | | | (+1,
-1) | | Class Signifier Family Feud/Fortunes | | Culture: Television: Game Show: Quiz |
| | | | (+2,
-2) | | Classic Game | | Computer: Game: All-In-One |
| | | | (0) | | Classic Game Controllers w/ USB Connectors | | Computer: Game: Platform |
| | | | (+1,
-1) | | clay display and input device | | Computer: Display: 3D |
| | | | (+1,
-1) | | Clay Pizza Shooting | | Sport: Hunting |
| | | | (0) | | Clean Air Pipeline for Smog-filled Cities | | Home: Ventilation |
| | | | (0) | | clean closet | | Home: Laundry |
| | | | (0) | | Clean tuna can opener | | Food: Packaging: Can |
| | | | (0) | | cleaner soaker powder | | Product: Laundry Detergent |
| | | | (+1,
-1) | | Clear Body Panels | | Vehicle: Car: Body Panels |
| | | | (+1,
-1) | | Clear Fence | | Product: Fence |
| | | | (0) | | Clear Insulated Pitcher | | Product: Drink Accessory: Temperature |
| | | | (+1,
-1) | | Clear Popcorn Bags | | Food: Popcorn: Microwave |
| | | | (0) | | Clear Staples2 | | Product: Office Supplies: Staples |
| | | | (0) | | Clever Clock Clearance | | Product: Clock: Display: Analogue |
| | | | (0) | | Clickable Category Field | | Halfbakery: Layout: Link |
| | | | (+3,
-3) | | Clientele Signifiers | | Food: Restaurant: Theme |
| | | | (0) | | Climate Controlled Bath | | Home: Bathtub: Heating |
| | | | (0) | | Climb assist | | Vehicle: Elevator |
| | | | (+1,
-1) | | Climbing Stairs | | Public: Architecture: Feature |
| | | | (0) | | Clinker-built freeway lanes | | Vehicle: Road: Lane |
| | | | (0) | | Clip-on antenna | | Product: Cell Phone: Accessory |
| | | | (+1,
-1) | | Clip-on Everything | | Fashion: Hi-tech |
| | | | (+2,
-2) | | Clip Shirt | | Fashion: Shirt |
| | | | (0) | | Clipboard Attachment for Tablets | | Computer: Storage: Filing System |
| | | | (+1,
-1) | | ClipGuard | | Product: Glasses |
| | | | (+1,
-1) | | Clocks that run slower | | Product: Clock: Accuracy |
| | | | (0) | | clockwork orange peeler | | Product: Peeler |
| | | | (0) | | Clockwork R/C Car | | Product: Toy: Remote Controlled |
| | | | (0) | | Clog day | | Culture: Public Holiday |
| | | | (+2,
-2) | | Close-quarters ballista | | Product: Weapon: Projectile |
| | | | (0) | | Closed caption for PIP | | Product: Television: Subtitles |
| | | | (0) | | closed cell foam extruded in vacuum | | Vehicle: Aircraft: Airship |
| | | | (+1,
-1) | | closed incinerator | | Science: Energy: Bioenergy: Waste |
| | | | (0) | | closing time | | Computer: Keyboard: Keys |
| | | | (0) | | clothes cleaning for dummies | | Home: Laundry: Washing |
| | | | (0) | | Clothes Washdryer machine | | Product: Home electronics |
| | | | (0) | | Clothesline awning | | Home: Laundry: Clothesline |
| | | | (0) | | Clotted Cream Maker | | Product: Cooker |
| | | | (+1,
-1) | | Cloud boiler | | Computer: Hosting |
| | | | (+1,
-1) | | Cloud provisioned business | | Business: |
| | | | (+2,
-2) | | Clown Vision | | Product: Glasses: Filter |
| | | | (+2,
-2) | | Clutch Pedal Fuel Restrictor | | Vehicle: Car: Clutch |
| | | | (+1,
-1) | | C-Me-Here | | Product: Postcard |
| | | | (0) | | CNBC re-runs with time | | Culture: Television: News |
| | | | (0) | | CNN Tabloid News | | Culture: Television: News |
| | | | (+5,
-5) | | Cnut Roast | | Food: Sweet: Jello |
| | | | (0) | | CO2 Cartridge Fueled Plant Generator | | Product: Home electronics |
| | | | (+1,
-1) | | CO2 Egg Gun | | Product: Weapon: Gun: Non-Lethal |
| | | | (+4,
-4) | | CO2 Ice Cap | | Science: Terraforming: Temperature |
| | | | (+1,
-1) | | Coach your team from Internet | | Sport: |
| | | | (+3,
-3) | | Coal Powered Diesel SUV | | Vehicle: Car: Fuel: Alternative |
| | | | (+3,
-3) | | Coasting Laurels | | Fashion: Hat |
| | | | (0) | | coat picker | | Fashion: Coat |
| | | | (+1,
-1) | | Coated Diamond Coatings | | Science: Chemistry |
| | | | (0) | | Coax power plug | | Product: Plug |
| | | | (0) | | Co-branding with a real bakery | | Halfbakery: Merchandise: Food |
| | | | (+1,
-1) | | Cockpit Door Bar | | Vehicle: Airplane: Security: Hijacking |
| | | | (+3,
-3) | | Cockroach removal service | | Home: Pest Control: Removal |
| | | | (+1,
-1) | | Cocktail Weenie Buns | | Food: Bread: Shape |
| | | | (0) | | Coconut Oil Wall Insulation | | Home: Insulation |
| | | | (0) | | Code Block Namer | | Computer: Text Editor |
| | | | (0) | | Code Number Bumper Stickers | | Vehicle: Car: Cell phone |
| | | | (0) | | Coded Clock | | Product: Alarm Clock: Control |
| | | | (+2,
-2) | | Codephrase helps stop prison rape | | Public: Prison |
| | | | (0) | | Coffee Bar | | Food: Coffee |
| | | | (+1,
-1) | | Coffee Cup of Shame | | Business: Cafe |
| | | | (+1,
-1) | | Coffee Ground Centrifuge | | Food: Coffee: Brewing |
| | | | (+4,
-4) | | coffee jacket | | Fashion: Temperature: Heating |
| | | | (0) | | Coffee-pot Overflow Failsafe | | Food: Coffee: Brewing |
| | | | (+2,
-2) | | Coffee Table Mantlet | | Home: Warniture |
| | | | (0) | | Coffee Table Remote | | Product: Remote: Universal |
| | | | (0) | | coffee tea reusable portable filter | | Food: Coffee |