Daughter understood the meaning of fear (5)
I believe the answer is:
dread
'meaning of fear' is the definition.
'dread' can be an answer for 'fear' (dread is a kind of fear). I'm not sure about the 'meaning of' bit.
'daughter understood' is the wordplay.
'daughter' becomes 'd' (genealogical abbreviation).
'understood' becomes 'read' (I've seen this in another clue).
'd'+'read'='DREAD'
'the' is the link.
Can you help me to learn more?
(Other definitions for dread that I've seen before include "Great fear or apprehension" , "quail" , "Terror" , "Hairstyle" , "Enormous apprehension" .)