Fancy horse that's hugging rails initially (6)
I believe the answer is:
frilly
'fancy' is the definition.
(I've seen this before)
'horse that's hugging rails initially' is the wordplay.
'horse' becomes 'filly' (I have seen 'Female horse ' mean 'filly' so perhaps 'horse' could also mean 'filly').
'that's hugging' indicates putting letters inside (outside letters hug or embrace inside letters).
'rails initially' becomes 'r' (I can't justify this - if you can you should believe this answer much more).
'filly' going around 'r' is 'FRILLY'.
Can you help me to learn more?
(Other definitions for frilly that I've seen before include "ruffled" , "Fancy" , "Having flounces, ruffles, etc" .)