beta particle beta orionis • beta radiation · · · Info · Definitions · Characters · · beta particle · · Text Common · · Latin · · Scripts 13 · · Length 5 · · Syllables Definitions · · · (noun) a high-speed electron or positron emitted in the decay of a radioactive isotope. Synonyms: beta particle. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 b latin small letter b U+0062 c latin small letter c U+0063 e latin small letter e U+0065 i latin small letter i U+0069 l latin small letter l U+006C p latin small letter p U+0070 r latin small letter r U+0072 t latin small letter t U+0074