Everything in fire sale initially comes down (5)
I believe the answer is:
falls
'comes down' is the definition.
('fall' can be a synonym of 'come down')
'everything in fire sale initially' is the wordplay.
'everything' becomes 'all' (all things).
'in' indicates putting letters inside.
'initially' indicates taking the first letters.
The initial letters of 'fire sale' is 'fs'.
'all' inserted inside 'fs' is 'FALLS'.
(Other definitions for falls that I've seen before include "American seasons" , "Drops" , "Victoria or Niagara, for example" , "North Country force" , "See 6 Down" .)