I. adverb Date: 1840 with the head or front making the initial contact , in direct opposition, confrontation, or contradiction , II. adjective Date: 1903 having the front facing in the direction of initial contact or line of sight , frontal 2b
HEAD-ON
Meaning of HEAD-ON in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012