Definition of alpha in English:


Syllabification: al·pha
Pronunciation: /ˈalfə


  • 1The first letter of the Greek alphabet (Α, α), transliterated as ‘a.’.
    More example sentences
    • He named them using the first two letters of the Greek alphabet, alpha and beta.
    • Her talent scarcely runs the gamut from A to alpha minus.
    • It's five characters, all alphas, and probably all lower case.
  • 1.1 [as modifier] Denoting the first of a series of items or categories, e.g., forms of a chemical compound: alpha interferon the α and β chains of hemoglobin
    More example sentences
    • Three additional categories approached significance at the adjusted alpha levels.
    • The log power of activity in delta, theta, alpha, sigma, and beta bandwidths was computed.
    • Results showed hypnotic trait effects on skin resistance, heart and respiratory rate as well as on EEG theta, alpha, beta and gamma relative power changes.
  • 1.2 [as modifier] Zoology & Sociology Denoting the dominant animal or human in a particular group: the pack is a tightly knit, highly organized group, led by an alpha wolf See also alpha male.
    More example sentences
    • Periodically, fights broke out between the males as they competed for the coveted role of alpha grouse.
    • When groups were merged, once again, only a single alpha individual could be identified.
    • This pair is monogamous although, with the death of an alpha individual, a new alpha male or female will emerge and take over as the mate.
  • 1.3 [as modifier] informal Denoting a person who has a dominant role or position within a particular sphere: take turns cooking for each other if one of you is too much of an alpha chef
    More example sentences
    • He is now doing a complete makeover of the house of Atlanta's alpha chef.
    • Just a few seats away, the model Kate Moss—a kind of alpha trend-setter—was wearing a black monkey fur coat over a lace miniskirt that looked like a Victorian vintage piece.
    • The unloved school swots of the 20th century have blossomed into the alpha group of the 21st.
  • 1.4 short for alpha test.
    More example sentences
    • A new build of Longhorn, Microsoft's follow-up to XP, has leaked, and although it's still an alpha, reports of increased stability make it sound almost worth stealing.
    • The final release of the game is hardly better than the leaked alpha, which they said was nothing but a rough version, that needed polishing.
    • We weren't asked a cent for the privilege of downloading their music - presumably once Wippit gets out of alpha, the company will begin charging.
  • 1.5 (Alpha) [followed by Latin genitive] The first (typically the brightest) star in a constellation: Alpha Centauri
    More example sentences
    • And now, in a small nebula brimming with new lifeforms, ready and innocently waiting to see what the universe had in store for them, an Alpha lurks.
    • These alphas - named after the first letter in the Greek alphabet - are the brightest stars in their constellation, defining life as the young teen knows it.
  • 1.6 [as modifier] Relating to alpha decay or alpha particles: an alpha emitter
    More example sentences
    • Part of this energy is seen in the form of alpha radiation, which occurs in the process of alpha decay.
    • Helium, a light gas, is formed during radioactive alpha decay in rock minerals.
    • Similar damage is caused by the alpha recoil, which is a trace of the energy released during the alpha decay of uranium and thorium isotopes.
  • 2A code word representing the letter A, used in radio communication.
    More example sentences
    • We soon learned that the alpha bravo code is a type of phonetic alphabet used by NATO.
    • He states his 3-letter personal identification code, "ABC," to which the system responds in confirmation, "Alpha, Bravo, Charlie. Is that correct?"


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  • 1 (α) A plane angle.
  • 1.1 (α) Angular acceleration.
  • 1.2 (α) Astronomy Right ascension.


alpha and omega

The beginning and the end (especially used by Christians as a title for Jesus).
More example sentences
  • When Jesus talks about being alpha and omega, it offers the picture of someone at both ends of something, without middle ground.
  • A range of portable items have been found bearing Christian motifs such as the chi-rho, alpha and omega, or the representation of a fish.
  • A sign outside says in huge letters: Jesus said ‘I am the alpha and the omega, the beginning and the end’.
The essence or most important features: collective bargaining is seen as the alpha and omega of trade unionism
More example sentences
  • Why should one of the elect be bothered about table manners, if cognitive ability, without virtue or civility, is the alpha and omega of human excellence?
  • We are the alpha and the omega in seashore dining and freshly prepared gourmet seafood.
  • Instead, Jews and Judaism provided both the foundation of society and its hope for the future - they have become, if you will, the alpha and the omega of humanity.


from Semitic; cf. Phoenician’alp, lit. 'ox', and Hebrew’aleph 'aleph'.

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