To do with funny plays like 'Come on Dickheads!' (7)
I believe the answer is:
comedic
'to do with funny plays' is the definition.
I can't tell whether this defines the answer.
'come on dickheads' is the wordplay.
'on' means one lot of letters go next to another (in a down clue, letters appear on others).
'dickheads' becomes 'dic' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'come'+'dic'='COMEDIC'
'like' is the link.
Can you help me to learn more?
(Other definitions for comedic that I've seen before include "Like a joke" , "Amusing" , "Of humour" , "Cheerfully entertaining" , "description of light work in theatre" .)