Head stuck between bosoms, ones we've all seen before? (9)
I believe the answer is:
chestnuts
'ones we've all seen before?' is the definition.
I can't tell whether this defines the answer.
'head stuck between bosoms' is the wordplay.
'head' becomes 'nut' (informal term for somebody's head).
'stuck between' is an insertion indicator.
'bosoms' becomes 'chests' (I am not sure about this - if you are sure you should believe this answer much more).
'nut' put into 'chests' is 'CHESTNUTS'.
Can you help me to learn more?
(Other definitions for chestnuts that I've seen before include "often retold stories" , "horses" , "Tree fruits called conkers - some are edible" , "Common tree-fruits, sometimes roasted" .)