German agreed to visit rugby player with tetanus (7)
I believe the answer is:
lockjaw
'tetanus' is the definition.
(I know that tetanus can be written as lockjaw)
'german agreed to visit rugby player with' is the wordplay.
'german agreed' becomes 'ja' ('yes' in German).
'to visit' means one lot of letters goes inside another (inserted letters visit others).
'rugby player' becomes 'lock' (second row of a scrum).
'with' becomes 'w' (short for with).
'lock'+'w'='lockw'
'ja' going into 'lockw' is 'LOCKJAW'.
(Other definitions for lockjaw that I've seen before include "Popular name for tetanus" , "disease resulting" , "Serious condition" , "trap closer" , "Form of tetanus with rigidly closed mouth" .)