Dozes (off) (4)
(Other definitions for nods that I've seen before include "Is careless" , "gestures in agreement" , "is about to crash?" , "Signals assent" , "Makes mistake" .)
'dozes off' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for naps that I've seen before include "Span including short sleeps" , "Snoozes" , "Takes forty winks" , "Tips; sleeps" .)