thou

Mane

Pron

Nominative singular of ye (“you”).

Verb

1. To address (a person) using the pronoun thou, especially as an expression of contempt or familiarity.
2. To use the word thou.

Noun

A unit of length equal to one-thousandth of an inch (25.4 µm).

Noun

A thousand, especially a thousand of some currency (dollars, pounds sterling, etc.).

Adv

Misspelling of though.

Conj

Misspelling of though.

Wekî (IPA) tê gotin

/ðaʊ/

Etîmolojî

From Middle English thou, tho, thogh, thoue, thouȝ, thow, thowe, tou, towe, thu, thue, thugh, tu, you (Northern England), ðhu, þeou, þeu, þou (the latter three early Southwest England), from Old English þū, from Proto-West Germanic *þū, from Proto-Germanic *þū (“you (singular), thou”), from Proto-Indo-European *túh₂ (“you, thou”).
cognates and usage evolution
The English word is cognate with Saterland Frisian du (“thou”), West Frisian do (“thou”), dialectal Dutch du, dou, douw (“thou”), Limburgish doe (“thou”), Low German du (“thou”), German du (“thou”), Danish du (“thou”), Swedish du (“thou”), Faroese tú (“thou”), Icelandic þú (“thou”), Gothic 𐌸𐌿 (þu, “thou”), Latin tu, Ancient Greek σύ (sú) (Doric Ancient Greek τύ (tú), Greek εσύ (esý)), Irish tu, Lithuanian tu, Old Church Slavonic ty, Welsh ti, Armenian դու (du), Albanian ti, Persian تو (to).
The informality of thou and its replacement by ye in formal situations date only to the 14th century and come from French influence, since French (as many European languages, but not Old English) uses the second-person plural (vous) instead of the second-person singular (tu) as a mark of politeness or respect.