Any of several very large pelagic rays formerly of the genus Manta, now placed in genus Mobula, with winglike pectoral fins, a long tail, and two fins resembling horns that project from the head.

A stream of alpha particles.

Alternative spelling of ray gun

Alternative spelling of death ray

(figuratively) A person (or thing) that brings happiness into the lives of others.

(botany) any of the bands of cells in various trees extending across the wood from the pith to the bark / (anatomy) the middle part of a cortical lobule in the kidney

An ultrasoft X-ray used in treating various skin diseases.

Alternative form of Roentgen-ray

(of fish) In the Actinopterygii taxonomic class of fish, all having in common lepidotrichia (a kind of fin made of webs of skin supported by bony or horny spines).

Any of the group of rays of the order Torpedodiniformes, which can produce an electric discharge.