fifth

Etymology

PIE word *pénkʷe From Middle English fifthe, fifte, fift, from Old English fīfta (“fifth”), from Proto-Germanic *fimftô (“fifth”) or *femftô, equivalent to five + -th. Cognate with Scots fift, fyft (“fifth”), North Frisian fyfde (“fifth”), West Frisian fyfde (“fifth”), Dutch vijfde (“fifth”), Low German fifte, föfte, füfte (“fifth”), German fünfte (“fifth”), Danish femte (“fifth”), Swedish femte (“fifth”), Icelandic fimmta (“fifth”).

adj

1. The ordinal form of the number five.

noun

1. The person or thing in the fifth position.
2. One of five equal parts of a whole.
3. The fifth gear of an engine.
4. A quantity of liquor equal to one-fifth of a gallon, or, more commonly, 750 milliliters (that is, three quarters of a liter).
5. (music) The musical interval between one note and another five scale degrees higher (the fifth note in a scale)
   Now I've heard there was a secret chord / That David played, and it pleased the Lord / But you don't really care for music, do ya? / It goes like this, the fourth, the fifth 1984, Leonard Cohen (lyrics and music), “Hallelujah”, in Various Positions
6. The fifth voice in a polyphonic melody.

verb

1. (music) To sing in the fifth voice in a polyphonic melody.
   Another extension of strict organum is 'fifthing'. Fifthing is a note-against- note method of creating a two-part texture by improvising a second voice over the given tune, starting and ending each musical phrase at the octave and proceeding mainly in fifths above the tune at others times. 1996, Music in Early English Religious Drama: Minstrels playing, page 510
   Each of these three groups contributes some special insight into the nature of fifthing and the context in which it was practiced. 1978, Discant and the Theory of Fifthing
2. (transitive) To support something fifth, after four others have already done so.
   Though seconding (or fifthing) the praise for “BoJack Horseman” and “In Treatment,” I think I’ll use the majority of my space to discuss “You’re the Worst.” 2017, Critics Pick the TV Shows That Get Mental Health Right — IndieWire Survey
3. (transitive, nonstandard) To divide by five.
   3/5 has been through fifthing. 2/3 has been through thirding. Therefore, 3/5 now needs thirding and 2/3 needs fifthing 2006, Mathematics for Dyslexics: Including Dyscalculia, page 188