Of the faculties, thoughts, actions, looks, etc.: Intently bent or directed.

Of a person's eyes, thoughts, etc.: Steadily or intently directed towards or ‘fastened’ upon an object.

Keenly observant; acutely perceptive, penetrating; (in later use often of a look or gaze) that focuses intently or probingly on someone or something.

Of the faculties, looks, etc.: Directed with strained or keen attention; earnest, eager, keen; intense. Const. on, upon (†to).

= intent, adj. 2.

Not wrested or strained.

(un-, prefix1 affix 4.)