What is the meaning of Malleolus?

The bony prominence with a shape likened to a hammerhead, especially each of those at the distal end of the fibula or tibia, on either side of the ankle joint.

diminutive of malleus:

1. A small hammer or mallet.
2. A mallet-shoot or hammer-shaped slip or cutting; literally, a “little hammer.” A propagation method where a young, green shoot is harvested with a small, horizontal section of the older, woody branch still attached at the base. This “T” junction resembles a mallet — the older wood forms the “head” and the new shoot forms the “handle” — providing a sturdy, nutrient-rich base for new roots to develop.
3. A kind of fire-dart.
4. The tongue of a shoe buckle.

A small hammer or mallet.

A mallet-shoot or hammer-shaped slip or cutting; literally, a “little hammer.” A propagation method where a young, green shoot is harvested with a small, horizontal section of the older, woody branch still attached at the base. This “T” junction resembles a mallet — the older wood forms the “head” and the new shoot forms the “handle” — providing a sturdy, nutrient-rich base for new roots to develop.

A kind of fire-dart.

The tongue of a shoe buckle.

Source: wiktionary.org