coincide verb [I]  to happen at or near the same time, or to be the same or similar 
I timed my holiday to coincide with the children's school holiday.
His comments coincided with a survey this week which found that many children
 begin regular television watching before they are a year old.

coincidence noun [C] 
A coincidence is an occasion when two or more things happen at the same time, esp. in a way that is unlikely and surprising. 
You've had your hair cut in the same style as me - what a coincidence!

coincidental adj.

coincidentally adv. 
The highest scorers, coincidentally, were all women.

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