The blunt ball or ornament on the top of a mace, usually made of metal.

plural of mace head

A machine tool for cutting grooves, key seats, or slots; a slotting machine.

prayer wheel

A device used to determine the relative phase shift variations between two collimated beams derived by splitting light from a single source.

(US, informal) macaroni and cheese

(US, Canada) Alternative form of macaroni cheese

plural of machine translation

Ara militaris, a large parrot with mostly green plumage.

The paradox whereby aid agencies report the success of most of their programs, yet it is impossible to establish any significant correlation between aid and GDP growth in developing countries.