Keywords: dismissive, ignore, neglect
As a Verb or Adjective
1. To pay no real attention to what someone is saying or doing and to attach no importance to it. English = (be) dismissive, ignore, neglect.
2. To appear to pay attention to someone or to say you agree or approve when in fact you do not just in order to please them or to avoid a confrontation. English = humour someone. Idiomatic English = pay lip service to someone.
1. Used alone in response to something your conversational partner has said to appear to agree (when really you either don't agree or don't care one way or the other) or to actually mean "Yes... but so what?", "Yes, of course that's true..." and so on.