Cheers! Old man's providing food in bar (5)
I believe the answer is:
tapas
'food in bar' is the definition.
(I've seen this before)
'cheers old man's' is the wordplay.
'cheers' becomes 'ta' (both can mean thank you).
'old man's' becomes 'pa's' (both can mean someone's father).
'ta'+'pas'='TAPAS'
'providing' is the link.
(Other definitions for tapas that I've seen before include "Spanish eats" , "Pasta (anag) - Spanish bar food" , "sort of Spanish bar" , "What's served in Spanish bar" , "Spanish savouries" .)