Arch at entrance to large amphitheatre? (4)
I believe the answer is:
bowl
'amphitheatre?' is the definition.
(amphitheatre is a kind of bowl)
'arch at entrance to large' is the wordplay.
'arch' becomes 'bow' (I've seen this before).
'at entrance' suggests taking the first letters.
The first letter of 'large' is 'l'.
'bow'+'l'='BOWL'
(Other definitions for bowl that I've seen before include "See 20" , "Soup dish - roll a ball" , "Deep dish or basin" , "Play with tenpins" , "hollow" .)