[f. FISH sb.1 + DAY.] A day on which fish is eaten, usually in obedience to an ecclesiastical ordinance; a fast-day.
a. 1327. Pol. Songs (Camden), 151. Feyr on fyhshe day launprey ant lax.
c. 1440. Anc. Cookery, in Househ. Ord. (1790), 429. Take almondes and grynde hom when thai byn blounchet, and tempur hom, on fyssheday wyth wyn, and on flesheday with broth of flesh.
1564. Act 5 Eliz., c. 5. It shall not be lawfull to eate any flesh vpon any dayes now vsually obserued as fish dayes, or vpon any Wednesday now newly limited to be obserued as fish day.
1641. Smectymnuus, Vind. Answ., § 2. 12. In the Calendar Fish dayes are now called Fasting days.
1699. T. Brown, in R. LEstrange, Colloq. Erasm. (1711), 358. If it happened to be a fish-day, we had sometimes three whitings.