Alexander Schmidt, Shakespeare Lexicon and Quotation Dictionary

Serious, 1) not jesting, being or meant in earnest, grave, solemn: “I am more s. than my custom,” Tp. II, 1, 219. “make a common of my s. hours,” Err. II, 2, 29. “if thou beest capable of things s.” Wint. IV, 4, 791. “our scene is altered from a s. thing,” R2 V, 3, 79. “a weighty and a s. brow,” R2 V, 3, 79. “he did it with a s. mind,” III, 2, 80. “not worth his s. considering,” III, 2, 80 “O heavy lightness, s. vanity,” Rom. I, 1, 184. “lend thy s. hearing,” Hml. I, 5, 5. “what s. contemplation are you in,” Lr. I, 2, 150. “with a s. industry,” Cymb. III, 5, 111. “play with that which is so s.” IV, 2, 231. “for more s. wooing,” Per. IV, 6, 95.
2) weighty, important, not trifling: “on s. business,” LLL II, 31. All's II, 4, 41. Oth. I, 3, 268. “important and most s. designs,” LLL V, 1, 105. “our rash faults make trivial price of s. things we have,” All's V, 3, 61. “a servant grafted in my s. trust,” Wint. I, 2, 246. “I'll hence to London on a s. matter,” H6C V, 5, 47. Tim. II, 2, 219. Lr. IV, 5, 8. “there's nothing s. in mortality, all is but toys,” Mcb. II, 3, 98. “what else more s. importeth thee to know,” Ant. I, 2, 124.