It has its heroes - and some cowards (3)
I believe the answer is:
war
'it has its heroes' is the definition.
The definition suggests a singular noun which matches the answer.
'some cowards' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'WAR' is hidden in the letters of 'cowards'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for war that I've seen before include "Strife" , "Armed hostility" , "Open hostility" , "Period of hostilities" , "Combat" .)