Amount to
I believe the answer is:
are
'amount to' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for are that I've seen before include "(We/you/they) exist" , "Unit of land measure equal to 100 square metres" , "is for more than one" , "(We/they/you) exist" , "Era (anag.)" .)