The word thou is a second person singular pronoun in English. It is now largely archaic, having been replaced in almost all contexts by you. It is used in parts of Northern England and by Scots . Thou is the nominative form; the oblique/objective form is thee (functioning as both accusative and dative), and the possessive is thy or thine. When thou is the grammatical subject of a finite verb in the indicative mood, the verb form typically ends in -st, most often with the ending -(e)st (e.g., "thou goest"; "thou dost"), but in some cases just -t (e.g., "thou art"; "thou shalt"), although in some dialects of Old English (mainly in the North), this verb form ended in -s, hence the Quaker habit of using what looks like the third person form of the verb with "thee" as the subject (paralleling the usage of "you"). In Middle English, thou was sometimes abbreviated by putting a small "u" over the letter thorn: .

Louis-Marie Aubert du Petit-Thouars (5 November 1758, Bournois – 12 May 1831, Paris) was an eminent French botanist known for his work collecting and describing orchids from the three islands of Madagascar, Mauritius and Réunion.