Bit from conquistador (3)
I believe the answer is:
tad
'bit' is the definition.
(both can mean a small amount)
'from conquistador' is the wordplay.
'from' indicates a hidden word.
'TAD' can be found hidden inside 'conquistador'.
(Other definitions for tad that I've seen before include "Modest amount" , "Small bit" , "(A) bit, touch" , "Smidgen" , "Slight amount" .)