Sign one's expecting minor collision (4)

I believe the answer is:

bump

I believe this is a double definition.

'sign one's expecting minor' is the first definition.
(as in a baby bump)

'collision' is the second definition.
(I've seen this before)

(Other definitions for bump that I've seen before include "Lump caused by a blow" , "Jolt - collision - swelling" , "Raised mark left by blow" , "Slight collision" , "Collide with force or violence" .)

I've seen this clue in The Telegraph and The Times.

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