China 
Africa 
- Coherent states
- Coherent turbulent structures
- Cohesion
- Cohort
- Cohort analysis
- Coil
- Coil springs
- Coil-globule transition
- Coiled coil
- Coiled tubing
- Coiled-coil
- Coin toss
- Coin-OR
- Coincidence counting
- Coincidence point
- Coinfection
- Coining
- Cointegration
- Coir
- Coke
- Coke strength after reaction
- Coker unit
- Coking
- Col1a2
- Col3a1
- Colchicine
- Cold
- Cold blast
- Cold cathodes
- Cold chain
- Cold data
- Cold finger
- Cold fronts
- Cold injury
- Cold ironing
- Cold pad batch
- Cold rolled steel
- Cold seeps
- Cold sores
- Cold spraying
- Cold start
- Cold trap
- Cold welding
- Cold working
- Cold-formed steel
- Cole-Cole equation
- Colebrook equation
- Colectomy
- Colemanite
- Colic
- Coliform bacteria
- Colistin
- Colitis
- Collaborative filtering
- Collaborative mapping
- Collaborative product development
- Collaborative software
- Collagen
- Collagenase
- Collagenase clostridium histolyticum
- Collateral circulation
- Collecting duct
- Collection
- Collective intelligence
- Collective knowledge
- Collective operations
- Collectively exhaustive events
- Collets
- Colligative properties
- Collimated
- Collimated beam
- Collimators
- Collinear
- Collinearity
- Collision
- Collision attack
- Collision avoidance
- Collision avoidance system
- Collision cascade
- Collision domain
- Collision frequency
- Collision resistance
- Collision theory
- Collision zone
- Collision-induced dissociation
- Collodion
- Colloid mill
- Colloid vibration current
- Colloid-facilitated transport
- Colloidal crystals
- Colloidal gold
- Colloidal probe technique
- Colloidal silica
- Colloidal silver
- Colloids
- Colluvium
- Coloboma
- Colon
- Colon cancer
- Colonial
- Colonoscopy
- Colony
- Colony morphology
- Colony-stimulating factor
- Color
- Color appearance model
- Color blindness
- Color charge
- Color correction
- Color difference
- Color fastness
- Color histogram
- Color index
- Color management
- Color mixing
- Color models
- Color quality scale
- Color quantization
- Color rendering
- Color reproduction
- Color science
- Color space
- Color television
- Color temperature
- Color vision
- Color-coding
- Colorectal cancer
- Colorectal polyps
- Colored glass
- Colorimeters
- Colorimetric
- Colorimetric analysis
- Colorimetry
- Colossal magnetoresistance
- Colostomy
- Colostrum
- Colour fastness
- Coloured Petri nets
- Colpitts oscillator
- Colposcopy
- Coltan
- Columbite
- Column
- Column chromatography
- Column density
- Column family
- Column generation
- Column space
- Column vectors
- Column-oriented