A weak aurora above the tropics

Abbreviation of archaic. / Abbreviation of architectural.

(uncountable) Abbreviation of archaism. / (uncountable) Abbreviation of archery. / (countable) Abbreviation of archipelago. / (countable) Abbreviation of architect.

plural of arc-boutant

(finance) A theory of asset pricing serving as a framework for the arbitrage pricing model.

(finance) An asset pricing model using one or more common factors to price returns. With only one factor, representing the market portfolio, it is called a single factor model. With two or more factors, it is called a multifactor model.

(informal, Northern England) an extremely lucky person.

The Arabic script.

A device, usually made of leather with a metal ring, that is fastened around the penis and testicles to sustain erection.

(anatomy) An arch formed by the zygomatic process of the temporal bone and the temporal process of the zygomatic bone.