Circadian clock (plants)

Circle

Circuit (electronics)

Circuit breaker

Circuit cavity electromechanics in the strong-coupling regime

Circulating cancer cells

Circulation

Circulation disorders

Cirrhosis

Cirripedia

Cirrus clouds and climate

Cisplatin

Citric acid

Citric acid cycle

Citron

Citronella

Citrus greening disease

Civet

Civil engineering

Cladding

Cladoselache

Clarification

Classical field theory

Classical mechanics

Classical swine fever

Clathrate compounds

Clay

Clay minerals

Clear-air turbulence

Cleavage (developmental biology)

Cleft lip and cleft palate

Clevis pin

Click chemistry

Click chemistry in polymer science

Client-server system

Climate change and sex determination

Climate history

Climate modeling

Climatology

Clinical forensic nursing

Clinical immunology

Clinical microbiology

Clinical pathology

Clock (mechanical)

Clock paradox

Cloning

Closed-caption television

Closed-circuit television (CCTV)

Clostridioides difficile

Clostridium

Cloud

Cloud computing

Cloud forest

Cloud physics

Clove

Clover

Clupeiformes

Cluster ion mass spectrometry

Clutch

Clypeasteroida

Cnidaria

Coal

Coal balls

Coal chemical

Coal gasification

Coal liquefaction

Coal mining

Coal paleobotany

Coalbed methane

Coastal engineering

Coastal landform

Coastal plain

Coati

Coaxial cable

Cobalt

Coca

Cocaine

Coccidia

Coccolithophorida

Cochlear wave propagation

Cocoa powder and chocolate

Coconut

Coda wave interferometry

Coelacanthiformes

Coenopteridales

Coenurosis

Coenzyme

Coesite

Coevolution between flowering plants and insect pollinators

Coffee

Cofferdam

Cogeneration system

Cognition

Cognitive bias in forensic science

Cognitive radio

Cognitive technology

Cognitive-behavioral therapy

Coherence

Cohesion (physics)

Coining