Knotty little problem (5)
I believe the answer is:
hitch
This could be a double definition.
'knotty little' is the first definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'problem' is the second definition.
(I've seen this before)
Can you help me to learn more?
(Other definitions for hitch that I've seen before include "Thumb (a lift)" , "couple" , "Make fast" , "To travel without paying" , "Tether (rope); difficulty" .)