unprompted

From un- +‎ prompted.

unprompted (comparative more unprompted, superlative most unprompted)

1. Not prompted; not urged or instigated; spontaneous.

   Synonym: unstimulated

   Hyponym: unprovoked

   • 2018 December, Nathan Betancourt, Balázs Kovács, Sarah M. G. Otner, “The perception of status: How we infer the status of others from their social relationships”, in Network Science, volume 6, number 3, →DOI:

     The unprompted, rapid, and reliable emergence of hierarchical relationships within human social groups (Gruenfeld & Tiedens, 2010; Leavitt, 2005) means that differences in social status exist in perhaps all human social environments (Anderson & Kilduff, 2009; Gould, 2002; Ridgeway, 1991).

   • 2025 August 3, Adam Gabbatt, “‘He has trouble completing a thought’: bizarre public appearances again cast doubt on Trump’s mental acuity”, in The Guardian‎^[1], →ISSN:

     Donald Trump’s frequently bizarre public appearances, which this month have seen the president claim, wrongly, that his uncle knew the Unabomber and rant unprompted about windmills on his recent trip to the UK, have once again raised questions about his mental acuity, experts say.