from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Archaic A battle-ax with two cutting edges.
- n. Archaic A mattock with one blade like an ax and the other like an adz.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. An axe with two cutting blades
- n. A mattock
- n. A double bladed tool used in gate type hurdle making for cutting out mortices, with a flat chisel and a mortice chisel or hook, similar to the much larger french carpenter's tool, the bisaigue (or besaigue)
- n. A double-bladed halberd or battle-axe
from The Century Dictionary and Cyclopedia
- n. A double-bladed battle-ax, especially that carried by the Northern nations.
- n. A broadsword: so called from a misunderstanding of the word. See the quotation.
- n. A kind of double ax; a kind of mattock the blade of which has one end shaped like an ax and the other like an adz.
- n. A mortising-tool.
- n. A reaping-hook.
- n. Same as roaring boy (see roaring).
Middle English, from Old English : twi-, two; see dwo- in Indo-European roots + bil, billhook.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Middle English twibill, from Old English twibill, from twī- ("double") + bill ("edge, blade"). Note bill probably from German 'beil' or Dutch 'bijl' (axe) see also billhook (Wiktionary)