C. T. Onions, A Shakespeare Glossary

1. phr. “How's the day?,” What hour of the day is it? Tp. V. i. 3; “How say you?,” What is your opinion? What do you mean? Tp. II. i. 262 [254], Ham. II. ii. 190; “How so?,” How is that? Why? Wiv. III. v. 71, Troil. III. iii. 247.

2. at what price 2H4 III. ii. 42, Troil. IV. ii. 23, Per. IV. vi. 22.

3. orig. ellipt. for ‘How is that?’ or ‘How say you?’, hence=‘What!’ Meas. II. i. 72, Cæs. II. i. 312.