Article to stay incomplete, sadly (4)
I believe the answer is:
alas
'sadly' is the definition.
(I've seen this before)
'article to stay incomplete' is the wordplay.
'article' becomes 'a' (indefinite article).
'to stay' becomes 'last'.
'incomplete' means to remove the last letter.
'last' with its last letter removed is 'las'.
'a'+'las'='ALAS'
(Other definitions for alas that I've seen before include "-- and alack!" , "Expression of grief/pity" , "Cry of regret" , "More's the pity" , "Expression of regret" .)