- headlong (adv.)
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- late 14c., headling, also headlings, "headfirst (downward); headlong (forward); without thinking, hastily," from hed "head" (see head (n.)) + adverbial suffix -ling. Altered by c. 1400 to conform with sidelong, etc. Its true companions are now mostly obsolete: darkling, backling, flatling, etc.