(physics) A positively charged nucleus of a helium-4 atom (consisting of two protons and two neutrons), emitted as a consequence of radioactivity; α-particle

A secondary structure found in many proteins, in which the amino acids are arranged in a coil, or helix, with almost no free space on the inside and all side chains being pointed towards the outside

(zoology, ethology) the dominant female animal in a pack / (by extension) a self-assured and strong woman; an alphette

The person in a group who displays the most experience or knowledge, especially with respect to technology.

(computing, technology) An early version of a program or application, typically unstable, but useful to show what the product will do. Sometimes this stage is referred to as a preview version. Sometimes no more features are added after this release, but bug fixes continue. This release comes after a pre-alpha version and before a beta version. As opposed to a beta version an alpha version is usually not feature complete.

(software, testing) A process where a software application approaching full functionality is made available to a group of sophisticated users.

(physics) a radioactive substance that decays by emitting alpha particles

A stream of alpha particles.

(neurology) An electrical signal produced by the brain while the subject is relaxed.

An exclamation denoting surprise.