Pig runs away, seeing snake (3)
I believe the answer is:
boa
'snake' is the definition.
(I know that boa is a type of constrictor)
'pig runs away' is the wordplay.
'pig' becomes 'boar' (male pig).
'runs' becomes 'r' (cricket abbreviation).
'away' suggests deleting specific letters.
'boar' with 'r' removed is 'BOA'.
'seeing' is the link.
(Other definitions for boa that I've seen before include "Python" , "Non-venomous snake" , "One covered in scales" , "Wrap" , "S American snake that crushes its prey" .)