A little toad but no hole? (3)
I believe the answer is:
tad
'a little' is the definition.
(both can mean a small amount)
'toad but no hole?' is the wordplay.
'but no' is a deletion indicator.
'hole?' becomes 'O' (O looks like a hole).
'toad' with 'o' taken out is 'TAD'.
(Other definitions for tad that I've seen before include "Modest amount" , "Small bit" , "little boy" , "(A) bit, touch" , "A small amount (colloq.)" .)