(chemistry) monatomic hydrogen that exists transiently after the reduction of a hydrogen ion; generated from zinc and hydrochloric acid; it is a strong reducing agent

(ichthyology) Of a fish's tail, such that the vertebral column bends and extends upwards into the upper lobe of the tail, making it larger than the lower lobe; as in sharks, rays, and skates.

plural of equivalence gate

present participle of reinter