mayday!mayday! this is an emergency! i'm stuck on one clue in mos prize crossword,it goes;'collapsible headwear for theatre goers, and the pattern is;a-i-a-a-,please help.
THe nearest I can get to your letter structure is ALINASEL which is a medical term to do with the nose. I can see the link to an operating theatre.
Its something to do with a collapsible bone structure,
Hope that helps
Philip
An OPERA HAT is a collapsible top hat which was used by opera/theatre goers in times gone by. I know it doesn't match a couple of your letters, but it fits the clue quite well.