Concern (4)
'concern' is the definition.
(both can mean an affair or happening)
This is all the clue.
(Other definitions for matter that I've seen before include "Issue - stuff" , "It has mass and occupies space" , "Be of significance" , "From which all physical things are made" , "Stuff - mean something" .)
'concern' is the definition.
(I know that affair is a type of concern)
This is the entire clue.
(Other definitions for affair that I've seen before include "See 23" , "Amour" , "Thing to be done with raffia" , "Involvement" , "Singular business" .)
'concern' is the definition.
(I know that concern can be written as worry)
This is all the clue.
(Other definitions for worry that I've seen before include "Bother" , "'Anxiety, uneasiness (5)'" , "Harry" , "Concern, anxiety, uneasiness" , "Fret, be disturbed in mind" .)
'concern' is the definition.
(I know that interest is a kind of concern)
This is all the clue.
(Other definitions for interest that I've seen before include "Charge or payment for the use of money" , "Deep concern - premium paid for use of money" , "Concern or pastime" , "Proceeds" , "something that is enjoyable" .)
'concern' is the definition.
(I know that concern can be written as care)
This is all the clue.
(Other definitions for care that I've seen before include "Mind" , "See 16" , "Prudence" , "Safekeeping" , "Serious attention and thought" .)