adv. [f. ALERT a. + -LY2.] In an alert manner; on the watch to act; hence, briskly, actively, nimbly.
1787. Mrs. Delany, Corr., Ser. 2, III. 454. She is as upright, and walks as alertly, as when you saw her.
1865. Carlyle, Fredk. Gt., IX. XX. ix. 168. Henri had to … stand alertly on his guard.
