Absolutely not getting lift, crash (3,3)
I believe the answer is:
nod off
'crash' is the definition.
(both can mean to fall asleep)
'absolutely not getting lift' is the wordplay.
'absolutely not' becomes 'no' (both can be used to deny or reject something).
'getting' is a charade indicator (letters next to each other).
'lift' becomes 'doff' (as in to doff one's hat).
'no'+'doff'='NOD OFF'
(Other definitions for nod off that I've seen before include "Fall asleep casually" , "Doze" , "Become drowsy with moving cranium" , "'Fall asleep (3,3)'" , "Fall asleep with bobbing head" .)