In terrible tangle, I'm forming a bond (8)
I believe the answer is:
ligament
'a bond' is the definition.
(I know that ligament is a type of bond)
'in terrible tangle i'm' is the wordplay.
'in terrible' is an anagram indicator (I've seen this in other clues).
'tangle'+'im'='tangleim'
'tangleim' anagrammed gives 'LIGAMENT'.
'forming' is the link.
(Other definitions for ligament that I've seen before include "Fibrous tissue joining bones or cartilage" , "Tissue joining bones or cartilages" , "Tough band in joint" , "Joint connector" , "sheet of tissue" .)