Mark takes new heart from this narrow escape (5)
I believe the answer is:
scare
'this narrow escape' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'mark takes new heart' is the wordplay.
'mark' becomes 'scar' (mark left by an injury).
'takes' says to put letters next to each other.
'heart' indicates the central letters.
The centre of 'new' is 'e'.
'scar'+'e'='SCARE'
'from' is the link.
Can you help me to learn more?
(Other definitions for scare that I've seen before include "Panic" , "Health worry" , "Greatly frighten" , "Frighten or intimidate" , "Startle" .)