Cabin, a small, roughly built hut or shelter; the term is particularly applied to the thatched mud cottages of the negro slaves of the southern states of the Unites States of America, or of the poverty-stricken peasantry of Ireland or the crofter districts of Scotland. In a special sense it is used of the small rooms or compartments on board a vessel used for sleeping, eating or other accommodation. The word in its earlier English forms was cabane or caban, and thus seems to be an adaptation of the French cabane; the French have taken cabine, for the room on board a ship, from the English. In French and other Romanic languages, in which the word occurs, e.g. Spanish cabaña, Portuguese cabana, the origin is usually found in the Medieval Latin capanna. Isidore of Seville (Origines, lib. xiv. 12) says: - Tugurium (hut) parva casula est, quam faciunt sibi custodes vinearum, ad tegimen seu quasi tegurium. Hoc rustici Capannam vocant, quod unum tantum capiat (see Du Cange, Glossarium, s.v. Capanna). Others derive from Greek κάπη, crib, manger.
Skeat considers the English word was taken from the Welsh caban, rather than from the French, and that the original source for all the forms was Celtic.