adverb
Origin: LME hedlong, altered (by assoc. with along) < ME hedelinge(s) < hede, head + -linge, adv. suffix
adjective
See headlong in American Heritage Dictionary 4
adverb
Origin:
Origin: From Middle English (bi) hedlong
Origin: , alteration of (bi) hedling
Origin: : hed, head; see head
Origin: + -ling, in a specified direction; see -ling2
.Learn more about headlong