Alexander Schmidt, Shakespeare Lexicon and Quotation Dictionary

Anon, soon, presently, immediately after: “a. their loud alarums he doth hear,” Ven. 700. Ven. 700 Lucr. 433. Sonn. 33, 5. Pilgr. 79. Pilgr. 79 Tp. II, 2, 83. Tp. II, 2, 83 Wiv. III, 2, 87. 3, 180. IV, 2, 41. IV, 2, 41 Meas. IV, 1, 23. 2, 162. 2, 162 5, 13. V, 364. Mids. II, 1, 17. III, 2, 18. III, 2, 18 IV, 1, 183. V, 145. Merch. II, 2, 125. 9, 97. III, 5, 91. As II, 1, 52. Shr. Ind. 1, 130. All's I, 3, 133. IV, 1, 68. H4B II, 4, 187. H5 IV, 1, 26. H6A IV, 7, 19. H6B V, 1, 159. H6C III, 1, 2. R3 I, 4, 168. III, 1, 39. Rom. I, 4, 85. Mcb. V, 5, 34. Hml. V, 1, 309 etc. etc. Used as answer to a call: Rom. II, 2, 137. II, 4, 111. Mcb. II, 3, 22; especially by waiters, instead of the modern “'coming':” H4A II, 1, 5. 4, 29. 4, 29 4, 29 4, 29 4, 29 4, 29 4, 29 4, 29 H4B II, 4, 306.
Used instead of a repeated sometimes, now, or then: “sometime he trots, anon he rears upright,” Ven. 279. “sometime he scuds far off, a. he starts,” Ven. 279 “sometimes they do extend their view right on, a. their gazes lend to every place,” Compl. 26. “now proud as an enjoyer and a. doubting the filching age will steal his treasure,” Sonn. 75, 5. “who now hangeth like a jewel in the ear of caelo, and a. falleth like a crab,” LLL IV, 2, 6. “now the ship boring the moon, and a. swallowed,” Wint. III, 3, 94. “then stops again, strikes his breast hard, and a. he casts his eye against the moon,” H8 III, 2, 117.
Ever and a. == every now and then: “ever and a. they made a doubt,” LLL V, 2, 102. “a pouncetbox which ever and a. he gave his nose,” H4A I, 3, 38. In the same sense still and a.: “like the watchful minutes to the hour still and a. cheer'd up the heavy time,” John IV, 1, 47 (Corrupted to “still an end,” Gentl. IV, 4, 67).
Till a. == for a moment: Ant. II, 7, 44.