headfirst

With the head in front; headlong.not-comparable

Rashly; precipitately; without deliberation; hastily.not-comparable

• Sheffield was not going to stop being Sheffield just because he had dived headfirst into the lusts of the flesh.
• 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.

With the head in front; headlong.not-comparable