Hat that is carrying the head? (6)
I believe the answer is:
beanie
'hat' is the definition.
(I've seen this before)
'that is carrying the head?' is the wordplay.
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'carrying' means one lot of letters go next to another (in a down clue, the bottom letters carry others).
'the head?' becomes 'bean' (bean is a kind of head).
'ie' after 'bean' is 'BEANIE'.
(Other definitions for beanie that I've seen before include "Small close-fitting hat" , "cap" , "Topping" , "one on the head" .)