Gather to see lambs frolicking (8)
I believe the answer is:
assemble
'gather' is the definition.
(I know that gather can be written as assemble)
'see lambs frolicking' is the wordplay.
'frolicking' indicates an anagram.
'see'+'lambs'='seelambs'
'seelambs' is an anagram of 'ASSEMBLE'.
'to' acts as a link.
(Other definitions for assemble that I've seen before include "Manufacture" , "Bring/come together" , "Gather or collect together" , "Put together all the components" , "Build" .)