Bigheads putting in time for themselves? (8)
I believe the answer is:
egotists
'bigheads putting in time for themselves?' is the definition.
I can't tell whether this definition defines the answer.
'bigheads putting in time for themselves?' is the wordplay.
'bigheads' becomes 'egos' (I've seen this in another clue).
'putting in' is an insertion indicator.
'time' becomes 't' (abbreviation).
'for themselves?' becomes 'ist' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
't'+'ist'='tist'
'egos' enclosing 'tist' is 'EGOTISTS'.
Can you help me to learn more?
(Other definitions for egotists that I've seen before include "People with exaggerated notions of their own importance" , "They have an exaggerated sense of their own importance" , "Self-centred self-seekers" , "The selfish" , "Conceited and self-centered people" .)