Most obvious nuisance, note, among cuts (8)
I believe the answer is:
plainest
'most obvious' is the definition.
('plain' can be similar in meaning to 'obvious')
'nuisance note among cuts' is the wordplay.
'nuisance' becomes 'pest' (I've seen this in other clues).
'note' becomes 'la' (musical note as in do-re-mi).
'among' becomes 'in' (eg among or in a group).
'cuts' means one lot of letters goes inside another (a group of letters 'cuts' into another word).
'la'+'in'='lain'
'pest' going around 'lain' is 'PLAINEST'.
(Other definitions for plainest that I've seen before include "Most unembellished" , "Least decorative" .)