headfirst

With the head in front; headlong.

Adjective

  1. With the head in front; headlong.

Origin

From head + first.

Adverb

  1. With the head in front; headlong.

    Antonyms: feet first

  2. Rashly; precipitately; without deliberation; hastily.
    • Sheffield was not going to stop being Sheffield just because he had dived headfirst into the lusts of the flesh. - 2016, Kerry Greenwood, Murder and Mendelssohn, Sydney: Allen and Unwin, page 245:
    • Over the past two years, Silicon Valley’s leaders and investors — many of whom had once forsworn involvement in weapons and war — have plunged headfirst into the military industrial complex. - 2025 August 4, Sheera...

Synonyms

headforemost headlong