one of the three districts, anciently under the government of a a reeve,  into which Yorkshire was divided, late 13c., from late Old English *þriðing, a relic of Viking rule, from Old Norse ðriðjungr "third part," from ðriði "third" (see third).

The initial consonant apparently was merged by misdivision with final consonant of preceding north, west, or east.

early 15c., "dissolved, of loose structure," also "morally lax" (senses all obsolete), from Latin resolutus, past participle of resolvere "untie, unfasten, loose, loosen" (see resolve (v.)).

It emerged c. 1500 in the sense of "determined, decided, absolute, final," especially in the phrase resolute answer, which was "common in 16th c." [OED]. The notion is of "breaking (something) into parts" as the way to arrive at the truth of it and thus make the final determination (compare resolution).

The word has been used from 1530s of persons, "determined in mind, having a fixed resolve." Related: Resolutely; resoluteness. In Middle English a resolutif was a medicine to dissolve and disperse hardened matter (c. 1400).

alternative spelling of plow (Middle English plouʒ, plouh, ploug). "The accepted spelling in England since 1700" [OED, which also notes that the final guttural began to disappear in 14c. but was retained longer in the north and Scotland]. Related: Ploughed; ploughing.

1640s, fort, from French fort "strong point (of a sword blade)," earlier "fort, fortress" (see fort). Meaning "strong point of a person, that in which one excels," is from 1680s. Final -e- added 18c. in imitation of Italian forte "strong."

denoting a mode or melody in Gregorian music in which the final is in the middle of the compass instead of at the bottom, 1590s, from Medieval Latin plagalis, from plaga "the plagal mode," probably from plagius, from Medieval Greek plagios "plagal," in classical Greek "oblique," from plagos "side" (from PIE root *plak- (1) "to be flat").