I. ˈhed-ˈȯn, -ˈän adverb
Date: 1840
1. : with the head or front making the initial contact
the cars collided head-on
2. : in direct opposition, confrontation, or contradiction
met the problem head-on
II. adjective
Date: 1903
1. : having the front facing in the direction of initial contact or line of sight
a head-on collision
2. : frontal 2b
a head-on confrontation