The actual word hobbit comes from the Rohirric word holbytla, which means 'hole-dweller.' In Westron, the common speech, the word for hobbit is kuduk, which is derived from the Rohirric kûd-dûkan, a synonym of holbytla. The Dúnedain refer to hobbits as 'Halflings,' which represents the Westron banakil, as hobbits are roughly half the height of a tall man. However, hobbits are not fond of this name, and certainly do not call themselves by it. They even consider it slightly offensive, and prefer just to be called hobbits. The Elves have names of their own for the little folk, as hobbits are oftentimes called in Bree, as opposed to Big folk, their term for men. In Quenya, the word is periando, and in Sindarin, it is perian. The plural form is periain, and the collective plural is periannath.
Tolkein, J.R.R. The Hobbit UK: George Allen & Unwin, 1937
Tolkein, J.R.R. The Lord of the Rings UK: George Allen & Unwin, 1954-1955