Almost lyrical about carbon fibre (7)
I believe the answer is:
acrylic
'fibre' is the definition.
(acrylic is a kind of fibre)
'almost lyrical about carbon' is the wordplay.
'almost' means to remove the first letter.
'about' indicates anagramming the letters.
'carbon' becomes 'c' (C is the chemical symbol for carbon).
'lyrical' with its first letter taken away is 'yrical'.
'yrical' anagrammed gives 'acryli'.
'acryli'+'c'='ACRYLIC'
(Other definitions for acrylic that I've seen before include "Pungent acid" , "Type of paint or textile fibre" , "Type of twenty Dn" , "Kind of paint" , "Shiny paint" .)