the.com/unresponsiveness

means The state of failing to react, reply, or engage — a person, system, or body that just won't answer back.

from Built from 'respond,' which traces to Latin respondere — 're-' (back) plus 'spondere' (to pledge or promise). To respond was originally to make a return pledge, like answering a vow with a vow. Add 'un-' and '-ness' and you get the noun for that pledge withheld: no answering vow comes back at all, just the dial tone of absence.