Alexander Schmidt, Shakespeare Lexicon and Quotation Dictionary

Vain, 1) empty, idle, unsatisfying, frivolous (German: nichtig): “beauty is but a v. and doubtful good,” Pilgr. 169. “have more time for --er hours and tutors not so careful,” Tp. I, 2, 174. “I will not hear thy v. excuse,” Gent. III, 1, 168. “train our intellects to v. delight,” LLL I, 1, 71. “brings in the champion Honour on my part against your v. assault,” All's IV, 2, 51. “leave thy v. bibble babble,” Tw. IV, 2, 105. the want of which v. dew (i. e. tears) Wint. II, 1, 109. “thy word is but the v. breath of a common man,” John III, 1, 8. “if heart's presages be not v.” R2 II, 2, 142. “how these v. weak nails may tear a passage,” V, 5, 19. “his addiction was to courses v.” H5 I, 1, 54. “your oath is v. and frivolous,” H6C I, 2, 27. “poor painted queen, v. flourish of my fortune,” R3 I, 3, 241. “a v. prophecy,” H8 I, 2, 147. “v. pomp and glory of this world,” III, 2, 365. “lose not so noble a friend on v. suppose,” Tit. I, 440. “hands, to do Rome service, are but v.” III, 1, 80 (idle, answering no purpose, superfluous). “begot of nothing but v. fantasy,” Rom. I, 4, 98. “not with v. thanks,” Oth. III, 3, 470. “O v. boast,” V, 2, 264.
2) unwise, foolish, silly: “my father would enforce me marry v. Thurio,” Gent. IV, 3, 17. “school-maids change their names by v. though apt affection,” Meas. I, 4, 48. “there's no man is so v. that would refuse so fair an offered chain,” Err. III, 2, 185. “one whom the music of his own v. tongue doth ravish,” LLL I, 1, 167. “it would ill become me to be v., indiscreet, or a fool,” IV, 2, 31. “O v. petitioner, beg a greater matter,” V, 2, 207. “love is . . . all wanton as a child, skipping and v.” V, 2, 207 “every beardless v. comparative,” H4A III, 2, 67. “speak to that v. man,” H4B V, 5, 48. “a v., giddy, shallow, humorours youth,” H5 II, 4, 28. “O v. fool,” Lr. IV, 2, 61.
3) not true; used a) of things, == fallacious: “all hope is v., unless his noble mother and his wife,” Cor. V, 1, 70. b) of persons, == false, deceitful: “'tis holy sport to be a little v., when the sweet breath of flattery conquers strife,” Err. III, 2, 27 (placed in the rhyme).
4) proud of petty things, conceited: “his general behaviour v., ridiculous and thrasonical,” LLL V, 1, 13. “the schoolmaster is exceeding fantastical, too too v.” V, 2, 532. “infusing him with self and v. conceit,” R2 III, 2, 166. “any rebel or v. spirit of mine,” H4B IV, 5, 172 (But in all these passages the word may have another meaning; cf. Vanity).
5) answering no purpose, ineffectual: All's III, 4, 25. R2 III, 2, 214. H4B II, 4, 431. H5 III, 3, 24. Hml. I, 1, 146. Lr. V, 3, 293.
Substantively, for v. == to no purpose, idly: “which the air beats for v.” Meas. II, 4, 12. Oftener in v. == to no purpose, ineffectually: Ven. 607. Ven. 607 Ven. 607 Lucr. 1023. Lucr. 1023 Lucr. 1023 Pilgr. 391. Tp. IV, 97. Meas. III, 1, 199. IV, 1, 6. LLL I, 1, 140. Mids. II, 1, 88. Mids. II, 1, 88 All's I, 3, 207 “(I love in v.).” Wint. V, 3, 140. R2 II, 1, 4. R2 II, 1, 4 H4B II, 3, 14. H6A V, 4, 85. H6B II, 1, 146. III, 2, 146. IV, 1, 77. IV, 1, 77 H6C I, 3, 21. II, 1, 135. Tit. I, 455. II, 3, 163. III, 1, 27. III, 1, 27 Rom. I, 4, 45. Tim. I, 1, 128. III, 5, 59. V, 1, 193. Lr. I, 1, 163. “it is in v.” Rom. II, 1, 41. Tim. V, 1, 119. Tim. V, 1, 119 Per. V, 1, 41.