coincidental

1 existing or occurring at the same period of time the nearly coincidental deaths of Princess Diana and Mother Teresa Synonyms coetaneous, coeval, coexistent, coexisting, coextensive, coincident, contemporary, concurrent, contemporaneous, coterminous, simultaneous, synchronic, synchronousRelated Words accompanying, attendant, attending, concomitant, incidentAntonyms asynchronous, noncontemporary, nonsimultaneous, nonsynchronous

2 present at the same time and place claims a connection between the proliferation of fast-food restaurants and the coincidental surge in the rate of obesity Synonyms accompanying, attendant, attending, coexistent, coexisting, coincident, concomitant, concurrentRelated Words contemporaneous, contemporary, simultaneous, synchronous; associated, collateral, connected, linked, related; consequent, resultant, resulting; ensuing, following, subsequent; accidental, casual, chance, fluky (also flukey), fortuitous, freak, incident, incidentalNear Antonyms unassociated, unconnected, unrelated