headlong (adv.)
- abruptly
- carelessly
- desperately
- express
- fast
- furiously
- harum-scarum
- hastily
- headfirst
- heedlessly
- helter-skelter
- hurriedly
- impetuously
- impulsively
- mad
- madly
- precipitately
- precipitously
- quick
- quickly
- rashly
- recklessly
- sharp
- sheer
- slam-bang
- slap-bang
- slapdash
- sudden
- suddenly
- wantonly
- wild
- wildly
headlong (adj.)
- abrupt
- accident-prone
- agile
- bluff
- bold
- breakneck
- breathless
- careless
- daredevil
- daring
- dashing
- desperate
- devil-may-care
- double-quick
- electrifying
- expeditious
- express
- fast
- fleet
- flying
- foolhardy
- furious
- harum-scarum
- hasty
- headfirst
- helter-skelter
- hotheaded
- hurried
- impatient
- impetuous
- impulsive
- light-footed
- lively
- mad
- mercurial
- nimble
- overeager
- overenthusiastic
- overhasty
- overzealous
- precipitant
- precipitate
- precipitous
- prompt
- quick
- rapid
- rash
- reckless
- running
- rushing
- sharp
- sheer
- shocking
- slam-bang
- slapdash
- snappy
- spanking
- speedy
- startling
- steep
- sudden
- surprising
- swift
- unanticipated
- unexpected
- unforeseen
- unlooked-for
- unpredicted
- vertical
- wanton
- wild
- winged
