Alec's unusual ties (5)
I believe the answer is:
laces
'ties' is the definition.
(lacing is a kind of tying)
'alec's unusual' is the wordplay.
'unusual' indicates anagramming the letters.
'alecs' is an anagram of 'LACES'.
(Other definitions for laces that I've seen before include "Shoestrings" , "Scale for shoe securers" , "Cords for fastening shoes" , "Cords for tying shoes" , "Scale for boot fasteners" .)