A machicolation.

(mineralogy) A mineral with the chemical formula Ca₆Si₆O₁₇(OH)₂, found in various colours.

(Britain, Australia, informal) Short for locum tenens. / (Britain, Australia, informal) A period working as a locum tenens.

A measure; a standard of measure; an instrument to determine dimensions, distance, or capacity; a standard / An act of measuring. / An estimate.