Behold British launch (3)
I believe the answer is:
lob
'launch' is the definition.
(thesaurus)
'behold british' is the wordplay.
'behold' becomes 'lo' (archaic exclamation meaning 'look!').
'british' becomes 'b' (abbreviation e.g. in BBC).
'lo'+'b'='LOB'
(Other definitions for lob that I've seen before include "Loft" , "Throw ball in high arc" , "Elevated shot" , "high return" , "Throw in high, slow arc" .)