Alexander Schmidt, Shakespeare Lexicon and Quotation Dictionary

Vail, vb. 1) tr. to lower, to let fall: “he --s his tail,” Ven. 314. “she --ed her eyelids,” Ven. 314 “v. your regard upon a wronged maid,” Meas. V, 20. “--ing her high-top lower than her ribs,” Merch. I, 1, 28. “France must v. her lofty-plumed crest,” H6A V, 3, 25. “do not for ever with thy --ed lids seek for thy noble father in the dust,” Hml. I, 2, 70. “did v. their crowns to his supremacy,” Per. II, 3, 42. Metaphorically: “v. your stomachs,” Shr. V, 2, 176. “Douglas . . . 'gan v. his stomach,” H4B I, 1, 129. “if he have power, then v. your ignorance,” Cor. III, 1, 98.*
Doubtful passage: “fair ladies . . . dismasked . . . are angels --ing clouds,” LLL V, 2, 297 (Johnson: letting those clouds which obscured their brightness sink from before them. Could it not possibly be == clouds letting down, bearing down, angels? As for the construction, cf. Hml. I, 2, 2. Lr. II, 2, 129).
2) intr. to bow, to stoop, to do homage: when she would with rich and constant pen v. to her mistress Dian, Per. IV Prol. 29.