ecˈtoderm noun (Gr derma skin; biology)

1. The outer layer of cells forming the wall of a gastrula
2. The tissues directly derived from this layer (also exˈoderm)

ectodermˈal or ectodermˈic adjective

ectoenˈzyme noun

An exoenzyme

ectogenˈesis noun (Gr genesis generation; biology)

1. Development outside the body
2. Variation in response to outside conditions

ectogenetˈic adjective

Produced by or characteristic of ectogenesis

ectogenˈic adjective

1. Of external origin
2. Ectogenous

ectogenous /ek-tojˈə-nəs/ adjective (biology)

Capable of living independently, or outside the body of the host (as some parasites)

ectogˈeny noun

The effect of pollen on the tissues of a plant

ecˈtomorph noun

1. (Gr morphē form) a person of light and delicate build, thought to accompany a type of personality characterized by alertness, inhibition and intellectual activity
2. Cf endomorph and mesomorph

ectomorphˈic adjective

ecˈtomorphy noun

ectoparˈasite noun

An external parasite

ectoparasitˈic adjective

ecˈtophyte noun (Gr phyton a plant; botany)

A vegetable ectoparasite

ectophytic /-fitˈik/ adjective

ecˈtoplasm noun

1. (Gr plasma something moulded) the outer layer of cytoplasm of a cell (biology)
2. A substance believed by some spiritualists to emanate from the body of a medium

ectoplasˈmic adjective

ectoplasˈtic adjective

Ectoprocˈta same as Polyzoa (see under poly-)

ecˈtosarc noun (Gr sarx, sarkos flesh; zoology)

Ectoplasm

ecˈtotherm noun

A cold-blooded animal

ectothermˈic adjective

ectothermˈy noun

ectotrophˈic adjective (Gr trophē food; botany)

Of a mycorrhiza, having its hyphae mainly on the outside of the root that it feeds

ectozōˈan noun and adjective

ectozōˈic adjective

ectozōˈon noun (pl ectozōˈa)

(Gr zōion animal) an animal ectoparasite

exo- /ek-sō- or ek-so-/

combining form

(often interchanging with ecto-) outside, opp to endo- and ento-

exobiologˈical adjective

exobiolˈogist noun

exobiolˈogy noun

The study of (possible) extraterrestrial life

exˈocarp noun (Gr karpos fruit; botany)

1. The outer layer of the part of a fruit which contains the seeds
2. The epicarp

exˈocrine adjective (Gr krīnein to separate; physiology)

Of glands, secreting through a duct

noun

An exocrine gland

exocytōˈsis noun (biology)

The discharge of the contents of internal vesicles from a cell

exocytōˈtic adjective

exˈoderm noun

1. Exodermis
2. Ectoderm

exodermˈal adjective

exoderˈmis noun

(Gr dermis skin) the outer cortex layer of a root

exoenˈzyme noun

An enzyme that functions outside the cell producing it, an ectoenzyme

exoergic /-ûrˈjik/ adjective (Gr ergon work; nuclear eng)

Of a process in which energy is released

exogamˈic or exogˈamous adjective

exogˈamy noun

1. (Gr gamos marriage) the practice of marrying only outside of one's own group
2. The union of gametes not closely related (biology)

exˈogen noun (obsolete)

A dicotyledon, so called because its stem thickens by layers growing on the outside of the wood

exogenetˈic adjective (medicine)

Not genetic, not caused by genetic factors

exogˈenous adjective

1. Growing by successive additions to the outside
2. Developing externally
3. Having an external origin

exogˈenously adverb

exonuˈclease noun

An enzyme which continuously cleaves nucleotides from one end of a nucleotide chain

exˈonym noun

(Gr onoma a name) a name for a town, country, etc in a foreign language

exophˈagous adjective

exophˈagy noun

(Gr phagein to eat) the custom among cannibals of eating only the flesh of persons not of their own kin

exˈoplanet noun

A planet that orbits a star other than the sun

exˈoplasm noun

Ectoplasm

exopˈodite or exˈopod noun

(Gr pous, podos foot) the outer branch of a crustacean limb

exopodˈitic adjective

exoskelˈetal adjective

exoskelˈeton noun

A hard supporting or protective structure secreted externally by the ectoderm

exˈosphere noun

(Gr sphaira sphere) the outermost layer of the earth's atmosphere, beyond around 500km from the surface of the earth

exospherˈic or exospherˈical adjective

exosporˈal adjective

exˈospore noun

1. (Gr sporos a seed) the outer layer of a spore wall
2. A spore formed by the extrusion of material from the parent cell

exosporˈous adjective

exotherˈmal or exotherˈmic adjective (Gr thermē heat; chem)

Involving the release of heat, esp during a reaction

exotherˈmally or exotherˈmically adverb

exothermiˈcity noun

exotoxˈic adjective

exotoxˈin noun (biology)

A toxin produced by a micro-organism and secreted into the surrounding medium