Stuck on bottom lh corner
21 across Heads away from din can pity silly behaviour (7) last letter Y
18 down covering it up dispose of regular income (7) S???E/D
20 down Nebulous amount of moneynfor choice chinese food (3 3) ??? S?M
Thanks so much emeritus mamyalynne and lie-in-king.
Been puzzling those for some time this afternoon, must be the lunchtime drink has slowed my brain down.