Definitions
1.AdjectiveOf two or more objects: being in the same location.
2.AdjectiveOf two or more events: occurring at the same time; contemporaneous.
3.AdjectiveOf two or more things: having the same qualities; being in accordance; consonant, matching.
4.AdjectiveChiefly followed by to: accompanying, concomitant, incident.
5.NounOne of multiple incidents or things which coincide with each other; a concomitant.