- coenurus
- coliform
- colour-cell
- comb jelly
- companion-cell
- conjugant
- conarium
- consortism
- continuum
- conus
- corepressor
- cornification
- corpus luteum
- creatine
- crista
- ctenophoral
- ctenophore
- cribrellum
- crinome
- criss-crossing
- crossing over
- cryptozoic
- ctenosome
- cuadrilla
- culmen
- depressor
- detorsion
- deuterostome
- demoid
- dichromatopsia
- dictyostele
- desma
- diandric
- diaster
- digenesis
- dioecism
- dialysate
- diapedetic
- diphygenetic
- diphygenic
- diphylectic
- diphylous
- diphyodont
- dictyosome
- diecious
- duplicature
- eccrinology
- ectochrome
- effector
- egest
- elaeoblast
- elaeoplast
- ecotone
- ectadenia
- ectogenesis
- ectoparasite
- egesta
- elaeocyte
- ecotype
- ectobronchium
- ectocondyle
- ectoskeleton
- electrotaxis
- electrotonus
- enantiobiosis
- empodium
- end-sheath
- endexine
- endoascus
- endomixis
- endoenzyme
- endomitousis
- endopleura
- entoblast
- entoplasm
- endonuclear
- endozoic
- energid
- ensisternum
- epacme
- epanthous
- epiderma
- epididymis
- epifauna
- epimorphosis
- epimysium
- epinephrine
- epiphragm
- epiplankton
- epiplasm
- epiplastron
- episome
- epistasis
- epistatic
- epithem
- equibiradiate
- equipotent
- endoadaptation
- endobiotic
- ergograph