Teamwork obstacles (4)
I believe the answer is:
egos
'teamwork obstacles' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for egos that I've seen before include "People's personal pride - the parts of them that are conscious" , "feelings of self-importance" , "Self-images" , "Lots of self-esteem" .)