Tibia \Tib"i*a\, n.; pl. Tibi[ae]. [L.]

1. (Anat.) The inner, or preaxial, and usually the larger, of the two bones of the leg or hind limb below the knee.

2. (Zo["o]l.) The fourth joint of the leg of an insect. See Illust. under Coleoptera, and under Hexapoda.

3. (Antiq.) A musical instrument of the flute kind, originally made of the leg bone of an animal.

Source: Webster's Revised Unabridged Dictionary (1913)