krep-
“body, form”body, shape, form
Root for body/form, yielding Latin corpus/corporis, English corpse, corps.
Discussion
The PIE root *krep- (body, form, outward shape) produced vocabulary for the physical body and its appearance across the IE branches.
Latin corpus (body — genitive corporis) is the central reflex and the source of an extensive English vocabulary: corpse (a dead body), corporeal (pertaining to the body), corporate (united into one body — a corporation is a legal body), incorporate (to take into the body), corps (a military body of soldiers), and corpulent (having a large body). The word corporation encodes a legal fiction: a group of people treated as a single body, a metaphor so naturalised that we forget it rests on a PIE root for physical form.
The Latin diminutive corpusculum (a small body) gave English corpuscle — a term used in both physics (corpuscular theory of light) and biology (blood corpuscles).
Sanskrit kr̥p- (form, beauty) preserves the Indo-Iranian reflex with a different semantic emphasis — form as beauty rather than form as mass.
Middle Irish cruth (form, shape, appearance) provides the Celtic reflex.
The root connects to *dʰeyǵʰ- (to mold, to shape — see the dough/fiction root) through the concept of formed substance: *dʰeyǵʰ- names the act of shaping, *krep- names the result — the body as shaped matter.
Notes
Pokorny 620. English corpse, corps, corporal, corporation, incorporate.