Almost drag your head, being serious (5)
I believe the answer is:
heavy
'being serious' is the definition.
(I've seen this in another clue)
'almost drag your' is the wordplay.
'almost' means to remove the last letter (almost the whole word is kept).
'drag' becomes 'heave' (I've seen this before).
'your' becomes 'y' (this could be a standard abbreviation which I don't know about).
'heave' with its last letter taken away is 'heav'.
'heav'+'y'='HEAVY'
'head' is the link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for heavy that I've seen before include "Oppressive" , "Villain" , "serious!" , "Mosque prayer leader" , "Weighty - ponderous" .)