A little lower (6)
'a little lower' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for heifer that I've seen before include "Farm animal" , "Cow that has borne one or no calves" , "beast" , "Female bovine that has not given birth" , "a little lower" .)
'a little lower?' is the definition.
(little cow - 'low' can mean to make a mooing sound)
This is the entire clue.
(Other definitions for calf that I've seen before include "Back of lower leg" , "Part of the leg - baby farm animal" , "Small neat" , "binding?" , "Animal that yields veal" .)