"an associate in office, employment, or labor," 1530s, from Middle French collègue (16c.), from Latin collega "partner in office," from assimilated form of com "with, together" (see com-) + leg-, stem of legare "send as a deputy, send with a commission," from PIE root *leg- (1) "to collect, gather." So, "one sent or chosen to work with another," or "one chosen at the same time as another."
the surgeon consulted his colleagues
collar-bone
collard
collate
collateral
collation
colleague
collect
collected
collectible
collectibles
collection