Hesitate to be the flag bearer? (5)

I believe the answer is:

waver

I'm a little stuck... Click here to teach me more about this clue!

'hesitate' is the definition.
(I know that hesitate can be written as waver)

I can't explain the rest of the clue.

(Other definitions for waver that I've seen before include "Begin to weaken" , "Be irresolute; flicker" , "Show hesitation, begin to give way" , "fluctuate" , "someone gesticulating wildly" .)

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app