Not reacting. It covers three situations that feel quite different but share one shape — you push, and nothing comes back. First, people: someone who does not answer your calls, emails or questions, or who sits there giving you nothing. 'The company was unresponsive to our complaints' means they ignored us. This is a polite, slightly cold way to say it, common in formal complaints because it sounds factual rather than angry. Second, and importantly, medicine: an unresponsive patient is not reacting to voice or touch — unconscious, or close to it. If you hear 'the patient was unresponsive on arrival', that is serious. Third, machines: an unresponsive screen or app has frozen; you tap it and nothing happens. It can also mean not affected by something, as in 'the tumour was unresponsive to treatment' — the treatment was tried, and the illness did not change. Note the word is neutral about blame. A person can be unresponsive because they are rude, or because they are hurt, or because they are unconscious; the word only reports the silence.