adjective. ['ˈhɛdˈfɝːst'] with the head foremost.
1. Adjective Debate is particularly helpful because the research requirements of debating encourage students to dive headfirst into political science literature. 2. Adverb You can dive headfirst into the glitter trend by applying some sparkle to each nail. 3. Noun, singular or mass Hoist the pig with your helper into the tub or scalding water, headfirst.
adverb. ['ˈhɛdˈfɝːst'] with the head foremost.