(physics) An energetic electron or positron produced as the result of a nuclear reaction or nuclear decay.

(organic chemistry) A lactam having a four-membered ring structure; a structural element of many antibiotics such as penicillin.

(publishing) A person who informally proofreads another person's text before the latter makes it available to the general public.

(computing) An early version of a program or application that contains most of the major features, but is not yet complete. Sometimes these versions are released only to a select group of people, or to the general public, for testing and feedback. This is the second major stage of development following the alpha version, and comes before the release candidate.

A radioactive substance emitting beta particles.

(pharmacology) A blocking agent, one of a class of drugs used to treat hypertension and control the rate at which the heart beats.

(neurology) An electrical signal produced by the brain while the subject mentally active.

(physics) A nuclear reaction in which a beta particle (electron or positron) is emitted.

plural of beta blocker

(biochemistry) Any artificial peptide made from beta-amino acids; used in some antibiotics in an attempt to counter resistance.