Something that is coincidental is the result of a coincidence and has not been deliberately arranged.
例句
Any resemblance to actual persons, places or events is purely coincidental...如与真人、真实地点或真实事件有雷同之处，纯属巧合。I think that it is not coincidental that we now have arguably the best bookshops in the world.我认为我们现在拥有了可以说是世界上最好的书店，这并非巧合。
英汉词典释义
adj.
巧合的,同时发生的
These parallels cannot be merely coincidental.这些相似之处不可能只是巧合。