Taking heart, being related (4)
I believe the answer is:
akin
'being related' is the definition.
('akin' can be a synonym of 'related')
'taking heart' is the wordplay.
'heart' means to look at the middle letters.
The middle of 'taking' is 'AKIN'.
(Other definitions for akin that I've seen before include "Related or similar - as a relative?" , "Of like nature or related" , "Having similar characteristics" , "not totally similar" , "Of a similar nature" .)