collate v.

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" (compare Old English ge-, German ge-). The prefix in Latin sometimes was used as an intensive.

Before vowels and aspirates, it is reduced to co-; before -g-, it is assimilated to cog- or con-; before -l-, assimilated to col-; before -r-, assimilated to cor-; before -c-, -d-, -j-, -n-, -q-, -s-, -t-, and -v-, it is assimilated to con-, which was so frequent that it often was used as the normal form.

"person devoted to religious work," especially "child dedicated by his or her parents to monastic life and raised and trained in a monastery and held in monastic discipline," 1756, from Medieval Latin oblatus, noun use of Latin oblatus, variant past participle of offerre "to offer, to bring before," from ob- (see ob-) + lātus "carried, borne," used as past participle of the irregular verb ferre "to bear."

Presumably lātus was taken (by a process linguists call suppletion) from a different, pre-Latin verb. By the same process, in English, went became the past tense of go. Latin lātus is said by Watkins to be from *tlatos, from PIE root *tele- "to bear, carry" (see extol), but de Vaan says "No good etymology available."