Cling to one's walking companion? (5)
I believe the answer is:
stick
'cling' is the definition.
(synonyms)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for stick that I've seen before include "See 2" , "Glue; piece of wood" , "Adhere; baton" , "Staff - criticism" , "Gear lever; adhere" .)