We have a right to get into fighting gear with expletives! (10)
I believe the answer is:
swearwords
'expletives' is the definition.
('swearword' can be a synonym of 'expletive')
'we have a right to get into fighting gear' is the wordplay.
'have' means one lot of letters go next to another.
'right' becomes 'r' (common abbreviation).
'to get into' is an insertion indicator.
'fighting gear' becomes 'swords' (I can't justify this - if you can you should give a lot more credence to this answer).
'we'+'a'+'r'='wear'
'wear' inserted inside 'swords' is 'SWEARWORDS'.
'with' is the link.
Can you help me to learn more?
(Another definition for swearwords that I've seen is " may be used in anger".)