Tater (4)
'tater' is the definition.
(synonyms)
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" .)