greg

flock, herd

Spelled greg · grex, genitive gregis, 'flock, herd'

Latin grex is a flock: gregarious people seek company, congregate means gather, and egregious once meant standing out from the flock.

Words built from it

gregarious — sociable and fond of company
Latin gregarius (belonging to a flock), from grex, gregis (flock), + English -ous
congregate — to come together in a group
Latin congregare: con- (together) + gregare (gather into a flock), from grex (flock)
egregious — outstandingly bad or shocking
Latin egregius (standing out from the flock), from ex (out of) + grex, gregis (flock)
aggregate — to gather things into a whole
Latin aggregare: ad- (to), becoming ag-, + gregare (gather into a flock), from grex (flock)
segregate — to separate or keep apart from a group
Latin segregare: se- (apart) + grex, gregis (flock)
desegregate — to end enforced separation between groups
de- (undo) + segregate, from Latin se- (apart) + grex, gregis (flock)

Gregorian — Contains greg, but comes from the name Gregorius, from Greek gregorein (be watchful), not Latin grex, gregis (flock).