Spanish cheer after headers from West Ham United (5)
I believe the answer is:
whole
'united' is the definition.
(similar in meaning)
'spanish cheer after headers from west ham' is the wordplay.
'spanish cheer' becomes 'ole' (I've seen this in another clue).
'after' says to put letters next to each other.
'headers from' says to take the initial letters (I've seen 'header from' mean this).
The initial letters of 'west ham' is 'wh'.
'ole' put after 'wh' is 'WHOLE'.
(Other definitions for whole that I've seen before include "Entire, undivided" , "undamaged" , "Total" , "In entirety" , "Complete, containing all the parts" .)