Stimulate class left without paper (6)
I believe the answer is:
kindle
'stimulate' is the definition.
(thesaurus)
'class left without paper' is the wordplay.
'class' becomes 'kind' (I've seen this in other clues).
'without' suggests deleting specific letters.
'paper' becomes 'ft' (newspaper the FT, Financial Times).
'left' with 'ft' taken out is 'le'.
'kind'+'le'='KINDLE'
(Other definitions for kindle that I've seen before include "E-book device" , "Ignite" , "Linked (anag)" , "Modern book store" , "Inflame" .)