His pa can be silly and imitative (5)
I believe the answer is:
apish
'imitative' is the definition.
(similar in meaning)
'his pa can be' is the wordplay.
'can be' is an anagram indicator.
'his'+'pa'='hispa'
'hispa' is an anagram of 'APISH'.
'silly and' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for apish that I've seen before include "Foolish; simian" , "Foppish" , "Silly" , "Stupid" , "Foolish; like a monkey" .)