Joshing in bar, they’re regularly ignored (6)
I believe the answer is:
banter
'joshing' is the definition.
(thesaurus)
'bar they're regularly ignored' is the wordplay.
'bar' becomes 'ban' (I've seen this before).
'regularly ignored' means one should take alternating letters (letters removed at regular intervals).
The alternate letters of 'theyre' are 'ter'.
'ban'+'ter'='BANTER'
'in' acts as a link.
(Other definitions for banter that I've seen before include "Playful exchange of teasing remarks" , "Rail" , "Light teasing repartee" , "Tease in good-humoured way" , "Light raillery" .)