Derision's upset the Puritans (9)
I believe the answer is:
ironsides
'puritans' is the definition.
The definition and answer can be both people as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
'derision's upset' is the wordplay.
'upset' indicates an anagram.
'derisions' anagrammed gives 'IRONSIDES'.
'the' is the link.
Can you help me to learn more?
(Other definitions for ironsides that I've seen before include "Those having great stamina" , "Cromwell's cavalry" , "Oliver Cromwell" , "one showing great fortitude" , "Several Edmunds" .)