éclat
n.
5Fr, noise, clap, splendor < =clater, to burst (out), shine, prob. < Gmc base seen in Langobardic slaitan, to tear, split, akin to SLIT6
1 brilliant or conspicuous success
2 dazzling display; striking effect
3 approval; acclaim
4 fame; renown

I remember with amusement and a bit of approval anecdote about poet Malherbe sandpapering
cuffs of new jacket "pour ôter cet éclat de neuf".

This appears to be a plural of adjective écrus.
ecru
adj., n.
5Fr =cru, unbleached, raw < OFr escru < es3 (L ex3), intens. + cru, raw < L crudus (see CRUDE): in reference to the color of unbleached linen6 light tan; beige

ectasis
1 definition found

From Webster's Revised Unabridged Dictionary (1913) [web1913]:


It is also a medical word meaning dilatation of a hollow organ.

Ectasis \Ec"ta*sis\, n. [L., fr Gr ?; ? out + ? to stretch.]
(Pros.)
The lengthening of a syllable from short to long.

From Forthright's Pgribtistery:
ecthlipsis
omitting one or more sounds in pronouncing a word
"P" silent as in bathing.

An individual characterized by ectomorphic habitus.
ectomorphic
adj.
5ECTO3 + 3MORPHIC6 designating or of the slender physical type, characterized by predominance of the structures developed from the ectodermal layer of the embryo, as skin, nerves, brain, and sense organs: cf. ENDOMORPHIC, MESOMORPHIC
ec#to[mor4phi[cal[ly
adv.
ec$to[mor#phy
n.

ectoparasite - a parasite that lives on exterior of its host. E.g/ fleas, lice.

ectophagous

Refers to an animal that feeds from the outside of a structure, such as a rabbit eating
bark from a shrub. See also: entophagous.

Principal usage to describe a tragic abnormal type of pregnancy, which usually requires
surgical intervention.
ectopic pregnancy
a pregnancy with the fertilized ovum developing outside the uterus, as in a Fallopian tube

"P" silent as in bathing.

I always heard that as "silent, like the P in swimming." (The bathtub's too small to indulge, but the pool, now, or better yet the ocean...)

prefix

Assuming you mean acclaim (éclat doesn't have a prefix) the root is clamare, to shout. The prefix is ad-, to (the d assimilated into the c of clamare).

So, the prefix directs the shouting of the root.