One way to bid (3)
I believe the answer is:
nod
'one way to bid' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for nod that I've seen before include "Gesture of assent" , "Move head in agreement" , "Indicate agreement (or sleepiness!)" , "Shake head in agreement" , "overlook something" .)