Did let a shape get enlarged (7)
I believe the answer is:
dilated
'enlarged' is the definition.
(I've seen this before)
'did let a shape' is the wordplay.
'shape' is an anagram indicator.
'did'+'let'+'a'='didleta'
'didleta' with letters rearranged gives 'DILATED'.
'get' is the link.
(Other definitions for dilated that I've seen before include "Made more open/wide" , "Opened up" , "like pupils in the dark" , "Spoke at length" , "Made more open" .)