Promise leads to halting puzzle (4,4)
I believe the answer is:
word game
'puzzle' is the definition.
'promise leads to halting' is the wordplay.
'promise' becomes 'word' (as in 'I give you my word').
'leads' is a charade indicator (letters next to each other).
'to halting' becomes 'game' (both can describe a deformed or injured leg).
'word'+'game'='WORD GAME'
(Other definitions for word game that I've seen before include "Scrabble or crossword, say" , "Eg, hangman" , "Eg, charades" , "Hangman, for example" , "anagram competition, say" .)