In distress it's seen by almost everybody as absolutely necessary (9)
I believe the answer is:
essential
'absolutely necessary' is the definition.
(I've seen this before)
'in distress it's seen by almost everybody' is the wordplay.
'in distress' indicates anagramming the letters.
'by' means one lot of letters go next to another.
'almost' means to remove the last letter (most of the word but not all of it).
'everybody' becomes 'all' (I've seen this in another clue).
'all' with its final letter removed is 'al'.
'its'+'seen'='itsseen'
'itsseen' with letters rearranged gives 'essenti'.
'essenti'+'al'='ESSENTIAL'
'as' acts as a link.
(Other definitions for essential that I've seen before include "Crucial" , "Vitally important" , "something necessary" , "Basic or necessary" , "So is certain oil-production" .)