Fibre from old ropes - or wood - universal material's origin (5)
I believe the answer is:
oakum
'fibre from old ropes' is the definition.
'oakum' can be an answer for 'fibre' (oakum is a kind of fibre). I'm not certain of the 'from old ropes' bit.
'wood universal material's origin' is the wordplay.
'wood' becomes 'oak' (oak is a kind of wood).
'origin' says to take the initial letters.
The initial letters of 'universal material' is 'um'.
'oak'+'um'='OAKUM'
'or' acts as a link.
Can you help me to learn more?
(Other definitions for oakum that I've seen before include "Tarred ropes teased out for caulking ships" , "Caulking material" , "ropy bits" , "One hand-picked" , "Tarred rope" .)