Unusual ways of behaving from those opposed, hundred inside (6)
I believe the answer is:
antics
'unusual ways of behaving' is the definition.
I can't tell whether this defines the answer.
'those opposed hundred inside' is the wordplay.
'those opposed' becomes 'antis' (I've seen this in another clue).
'hundred' becomes 'c' (Roman numeral).
'inside' means one lot of letters goes inside another.
'antis' going around 'c' is 'ANTICS'.
'from' acts as a link.
Can you help me to learn more?
(Other definitions for antics that I've seen before include "Cat's in (anag.)" , "Tomfoolery" , "comical capers" , "Absurd or foolish movements intended to amuse" , "Goings-on, absurd behaviour" .)