In England it means "nothing" or none, as in "Hey, do you have some spare change?" answer "I am sorry, I have nowt to give you."
Other English speakers may use "naught" (nothing, zero) in the same context.
Yes, "nowt" is slang for "nothing".
nowt
Nowt.
DOUBT
Nowt
Nowt.
He is gay, nowt wrong with that!
nowt egg
by doing nowt you silly sausage!
Hear all, see all and say nowt, ate all, sup all and pay nowt and if tha wants owt doing do it for thysen. Yorkshire position on wise action, careful and non wasteful use of resources and Independence.
nowt egg
nowt coz he ent got any