Throughout Tolkien's work, where characters use the Common Tongue, their words are represented by an English translation. So, references to the name 'Halfling' actually represent translations of the original Westron word, which was Banakil. Bana- here is equivalent to 'half' (the same element also seen in Banazîr, 'Half-wise', which was Sam Gamgee's true given name).

Note that 'Halfling' is quite distinct from 'Hobbit' in this context. The people living outside the Shire or Bree would use the name Banakil, but the Hobbits themselves used Kuduk, which is the word Tolkien renders as 'Hobbit'. For historical reasons, a related name Kûd-dûkan was found in Rohan, but outside these regions, Banakil was the usual name for this race.