Tater (4)
'tater' is the definition.
(I know that tater can be written as spud)
This is all the clue.
(Other definitions for spud that I've seen before include "Weeding spade" , "The popular potato" , "King Edward, say (slang)" , "short, stocky person" , "Weed spade" .)
(Other definitions for tot that I've seen before include "A wee dram" , "two fingers, perhaps" , "Add the little child?" , "Add; young child" , "Get the sum for the toddler" .)