a. (sb.) Forms: α. 1 ðrítiʓoða, þrittiʓoþa, þríteʓoða, þritteoʓoða, þreotteoʓaþa, þríteʓða, 2–3 þrittuþe, 3–4 þrittiþe, (3– teþe), 4 þrittype, thretyd, (Ayenb.) þrittaȝte, 4–5 thrittyde, threttithe, -yth, 5 thrydtythe, thryddyþ. β. (5 thyrttyest), 6 thyrteth, -ieth, thirteth, -ith, therttieth, 6– thirtieth. [OE. prítiʓoða, -e, f. þrítiʓ + -oða, -oðe (see -TH2), becoming in ME. þrittyþe, threttyth, in 16th c., by assimilation to the current form of the cardinal, thirtith, therttieth, thirtieth. Cf. ON. þrítugunde, -tugunde, -tegunde, later þrítugti. The WGer. langs. have a form in -ēsta, -esta, OFris. thrítegesta, OHG. drîzugôsto, Ger. dreissigste; so mod. Icel. þrítugasti: cf. Caxton’s thyrttyest.]
A. adj. The ordinal numeral belonging to the cardinal thirty; the last of thirty. The thirtieth man, the last man, or any one man, of thirty. Thirtieth part, one of the thirty equal parts into which anything may be divided.
c. 900. trans. Bæda’s Hist., V. xxii. [xxiii.] (1890), 482. Þy ðritiʓoðan [ʓere mines lifes].
a. 900. Martyrol., 88. On þone an ond þriteʓðan dæʓ.
c. 1000. Ælfric, Gram., xlix. (Z.), 283. Tricesimus, se þrittiʓoða [ðritoʓoða, þritteoʓoða].
c. 1200. Trin. Coll. Hom., 47. On þe two and þrittuðe dai.
1297. R. Glouc. (Rolls), 9129. In þe sixe & þrittiþe ȝer.
c. 1330. R. Brunne, Chron. Wace (Rolls), 1418. Þe þrittyþe day, lesse ne mo.
1340. Ayenb., 234. Þo þet byeþ ine spoushod … habbeþ þet þrittaȝte frut.
c. 1375. Sc. Leg. Saints, xxvi. (Nycholas), 560. He … syne þe thretyd psalme can say.
c. 1400. Maundev. (Roxb.), xxxiv. 155. In þe foure and thrittyde ȝere.
c. 1420. Chron. Vilod., 2182. In þe same thryddyþ day.
1483. Caxton, Gold. Leg., 350 b/2. The monke that was dede appierid on the thyrttyest day.
1530. Palsgr., 372/2. Trentiesme, thyrteth.
1579. Fulke, Heskins’ Parl., 390. The thirtieth Chapter beginneth the exposition.
1587. Golding, De Mornay, xvi. (1592), 258. Which of all the beastes hath so much as the thirtith part of them in his body?
1596. Dalrymple, trans. Leslie’s Hist. Scot. (S.T.S.), I. 167. The threttieth ȝeir of his regne.
Mod. Term ends on the thirtieth of June.
B. sb. A thirtieth part; in Eng. Hist. a thirtieth part of movable goods payable as an aid.
1800. Young, in Phil. Trans., XCI. 59. A thirtieth of an inch.
1825. J. Nicholson, Operat. Mech., 662. An addition of one-twentieth or one-thirtieth to the mass.
1893. J. A. Vincent, in Lanc. & Chesh. Rec. Soc., XXVII. 44. The great council, in which the king required a Thirtieth from the whole nation.
