Papers sometimes play lazily (4)
I believe the answer is:
idly
'lazily' is the definition.
(synonyms)
'papers sometimes play' is the wordplay.
'papers' becomes 'ID' (identifying documents are one's 'papers').
'sometimes' means one should take alternating letters (some of the letters are taken at regular intervals).
The alternate letters of 'play' are 'ly'.
'id'+'ly'='IDLY'
(Other definitions for idly that I've seen before include "So lacking purpose" , "Lazily, without due attention" , "in a careless manner" , "without good reason" , "without purpose" .)