1.InterjectionA general reassurance not to be concerned further with a subject.
Be reassured that it does not bother me; I am not concerned.
"Sorry if my music's bothering you. — No worries. I really like classical.; Thanks so much for the lift. — No worries, I had to go that way anyway.; I need this done by closing time. — No worries, I'll have it sorted."
2.InterjectionBe reassured that it does not bother me; I am not concerned.
"Sorry if my music's bothering you. — No worries. I really like classical."
3.InterjectionIt was no problem; not at all; you're welcome (particularly, though not strictly, when the favour being acknowledged was requested or in response to a difficulty, rather than spontaneous).
"Thanks so much for the lift. — No worries, I had to go that way anyway."
4.InterjectionDo not worry, I will do it.
"I need this done by closing time. — No worries, I'll have it sorted."