Heady, a.
Etymology: [From Head.]
1. Willful; rash; precipitate; hurried on by will or passion; ungovernable. All the talent required is to be hot, to be heady, -- to be violent on one side or the other. Sir W. Temple.
2. Apt to affect the head; intoxicating; strong. The liquor is too heady. Dryden.
3. Violent; impetuous. "A heady currance." Shak.
Shades of meaning
Fernald has no entry of its own for heady; he lists it under obstinate.
He lists it without comment; the entries above explain its neighbors.