With the head foremost; as, to fall headlong.
- With the head leading; headfirst: The runner slid headlong into third base.
- In an impetuous manner; rashly.
- At breakneck speed or with uncontrolled force.
- Done with the head leading; headfirst: a headlong dive.
- Impetuous; rash. See Synonyms at impetuous.
- Uncontrollably forceful or fast.
- Archaic Steep; sheer.