Swallow starts to execute acrobatic turn (3)
I believe the answer is:
eat
'swallow' is the definition.
(swallow can mean to consume or eat up)
'starts to execute acrobatic turn' is the wordplay.
'starts to' suggests taking the first letters.
'turn' becomes 't' (abbreviation in Oxford Dictionary of Abbreviations).
The first letters of 'execute acrobatic' is 'ea'.
'ea'+'t'='EAT'
(Other definitions for eat that I've seen before include "Corrode" , "Scoff" , "Munch" , "Have 23d [MEAL]" , "Use a knife and fork" .)