com-

a prefix meaning “with,” “together,” “in association,” and (with intensive force) “completely,” occurring in loanwords from Latin (commit): used in the formation of compound words before b, p, m: combine; compare; commingle.

Also, co-, col-, con-, cor-.

Origin

< Latin, variant of preposition cum with

British Dictionary definitions for com-

com-

prefix

together; with; jointly: commingle

Word Origin

from Latin com-; related to cum with. In compound words of Latin origin, com- becomes col- and cor- before l and r, co- before gn, h, and most vowels, and con- before consonants other than b, p, and m. Although its sense in compounds of Latin derivation is often obscured, it means: together, with, etc (combine, compile); similar (conform); extremely, completely (consecrate)

Word Origin and History for com-

word-forming element usually meaning "with, together," from Latin com, archaic form of classical Latin cum "together, together with, in combination," from PIE *kom- "beside, near, by, with" (cf. Old English ge-, German ge-). The prefix in Latin sometimes was used as an intensive.

Before vowels and aspirates, reduced to co-; before -g-, assimilated to cog- or con-; before -l-, assimilated to col-; before -r-, assimilated to cor-; before -c-, -d-, -j-, -n-, -q-, -s-, -t-, -v- assimilated to con-.

com- in Medicine

com- or col- or con-
pref.
Together; with; joint; jointly: commensalism.