Whĕn, adv.

(hwĕn), adv. [A-S. hwænne, hwĭnne, hwanne, hwonne, O. Sax. huan, O. Fries. hwenne, Goth. hvan, O. H. Ger. huanne, hwenne, M. H. Ger. wænne, N. H. Ger. wann, wenn, O. D. wan.] 1. At what time;—used interrogatively. When shall these things be? Matt. xxiv. 3. 2. At what time; at the time that; at or just after the moment that;—used relatively. Kings may Take their advantage when and how they list. Daniel.

3. While; whereas;—used in the manner of a conjunction to introduce an adversative clause, and equivalent to though at the same time; as, he chose to turn highwayman when he might have continued an honest man; he removed the tree when it was the best in the grounds.
4. Which time; then;—elliptically and inaccurately used as a substantive.

I was adopted heir by his consent; Since when his oath is broke. Shak. When was formerly used as an exclamation of surprise or impatience, like what! Come hither; mend my ruff: Here, when! thou art such a tedious lady! J. Webster. When as, at the time that; when. [Obs.] When as sacred light began to dawn. Milton.