- Chymotrypsin C
- Chymotrypsinogen
- Chytridiomycosis
- Ci protein
- Cib1
- Cibotium
- Cicatricial alopecia
- Cicatricial pemphigoid
- Cicer
- Ciclesonide
- Cicletanine
- Ciclopirox
- Ciclopiroxolamine
- Ciclosporin
- Cicutoxin
- Cidex
- Cidofovir
- Cigar smoking
- Cigarette smoking
- Cigarette smoking for weight loss
- Ciglitazone
- Ciguatera
- Ciguatoxin
- Cilansetron
- Cilantro
- Cilazapril
- Cilengitide
- Cilia
- Ciliary arteries
- Ciliary artery
- Ciliary body
- Ciliary ganglion
- Ciliary muscle
- Ciliary neurotrophic factor
- Ciliary process
- Ciliary processes
- Ciliogenesis
- Ciliopathies
- Ciliopathy
- Cilnidipine
- Cilofungin
- Cilomilast
- Cilostazol
- Cimetidine
- Cimino fistula
- Cinacalcet
- Cinchocaine
- Cinchona
- Cinchona alkaloid
- Cinchona officinalis
- Cinchona pubescens
- Cinchonine
- Cinchonism
- Cincinnati Prehospital Stroke Scale
- Cineangiography
- Cinemeducation
- Cineole
- Cineradiography
- Cingulate cortex
- Cingulate gyrus
- Cingulate sulcus
- Cingulotomy
- Cingulum
- Cinitapride
- Cinnabar
- Cinnamaldehyde
- Cinnamates
- Cinnamic acid
- Cinnamomum camphora
- Cinnamomum cassia
- Cinnamomum tamala
- Cinnamon
- Cinnamycin
- Cinnamyl acetate
- Cinnamyl alcohol
- Cinnarizine
- Cinoxacin
- Cinoxate
- Cipargamin
- Ciprofloxacin
- Ciproxifan
- Ciraparantag
- Circadian rhythm
- Circadian rhythm sleep disorder
- Circadian rhythm sleep disorders
- Circadian rhythms
- Circle of Friends
- Circle of Willis
- Circovirus
- Circuit training
- Circular RNA
- Circular dichroism
- Circular dichroism spectroscopy
- Circular folds
- Circulating endothelial cells
- Circulating free DNA
- Circulating tumor DNA
- Circulating tumor cells
- Circulation
- Circulatory system
- Circumcision
- Circumflex scapular artery
- Circumoral paresthesia
- Circumsporozoite protein
- Circumstantial speech
- Circumventricular organs
- Cirrhosis
- Cirsoid aneurysm
- Cis acting element
- Cis isomer
- Cis-2-Decenoic acid
- Cisapride
- Cisatracurium
- Cisplatin
- Cissampelos
- Cissampelos pareira
- Cissus
- Cistanche
- Cistanche deserticola
- Cisterna
- Cisterna chyli
- Cisterna magna
- Cistron
- Citalopram
- Citicoline
- Citraconic acid
- Citral
- Citrate
- Citrate synthase
- Citrates
- Citric acid
- Citric acid cycle
- Citrinin
- Citrobacter
- Citrobacter koseri
- Citron
- Citronella oil
- Citronellal
- Citronellol
- Citropten
- Citrullination
- Citrulline
- Citrullinemia
- Citrullinemia type I
- Citrullus colocynthis
- Citrus aurantium
- Citrus medica
- Civet
- Civility
- Clades