Adjective

1. easy; not difficult, not posing problems

   Finding this house should be no problem if we use a good map.

Interjection

1. certainly (said when granting a request)

   Porter, can you help me with my bags? — No problem, sir.

2. no thanks (or apology) is necessary (said in response to an expression of gratitude or regret)

   Thank you. — No problem.

   I'm sorry. — No problem.

Synonyms

• (no thanks (or apology) is necessary): don't mention it, it's nothing, it was nothing, not at all, no prob, no problemo, no probs, no worries, you're welcome, it's all right, that's OK