IPA: /ˈleɪtˌkoʊmər/
KK: /ˈleɪtˌkoʊmər/
A person or thing that arrives after the expected time or after others have already arrived.
The latecomer quietly entered the room after the meeting had started.
Latecomer → It is formed from "late" (from Old English *læt*, meaning delayed or after the expected time) and "comer" (from Old English *cuman*, meaning to come). A latecomer is someone who arrives after the expected time.
Think of someone who arrives 'after' ('late') the expected time — that's why a latecomer is someone who comes late.