Hot body that finally squeezes into short dress (4)
I believe the answer is:
star
'hot body' is the definition.
'star' can be an answer for 'body' (I have seen 'Celestial body' mean 'star' so perhaps 'body' could also mean 'star'). I'm not sure about the 'hot' bit.
'that finally squeezes into short dress' is the wordplay.
'finally' suggests the final letters.
'squeezes into' is an insertion indicator.
'short dress' becomes 'sar' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
The final letter of 'that' is 't'.
't' inserted inside 'sar' is 'STAR'.
Can you help me to learn more?
(Other definitions for star that I've seen before include "Five-pointed celestial body" , "One at the top of the bill" , "It twinkles" , "Famous person" , "The leading player is heavenly" .)