Definition of lambda in US English:

lambda

noun

  • 1The eleventh letter of the Greek alphabet (Λ, λ), transliterated as ‘l.’.

    • ‘For example, in the modern version, beta is veta or vita; delta is thelta; zeta is zita; eta is ita; theta is thita; lambda is lamvtha; tau is taf.’
    • ‘Einstein's 1917 refinement of his equations of gravity included a new term - denoted by the Greek letter lambda - in which his model universe neither expands nor contracts.’
    • ‘The cosmological constant, which Einstein signified by the Greek letter lambda, made it so.’
    • ‘Clearest are the differences between alphas, epsilons, and lambdas.’
    • ‘Before the suspense gets too much for everyone, I'll reveal the secrets of the symbol above - it's the lower-case Greek letter lambda.’
    1. 1.1LambdaAstronomy followed by Latin genitive The eleventh star in a constellation.
      ‘Lambda Tauri’
    2. 1.2Biology A type of bacteriophage virus used in genetic research.
      as modifier ‘lambda phage’
      • ‘Also, it is the surface receptor of the virus, bacteriophage lambda.’
      • ‘The sequence of the lambda and phiX174 bacteriophages9 provided the initial confidence booster for undertaking this project.’
      • ‘The second class of vectors are derived from the bacteriophage (bacterial virus) lambda.’
      • ‘Evidence that PP may play a dominant role in UV-induced transition mutagenesis has been obtained for bacteria and lambda phage.’
      • ‘The diagram below at right shows a virus that attacks bacteria, known as the lambda bacteriophage, which measures roughly 200 nanometers.’
    3. 1.3Anatomy The point at the back of the skull where the parietal bones and the occipital bone meet.
      • ‘Berry found sutural bones in 19th century Londoners in the vicinity of the lambda in 28.7% of men and 17.1% of women.’
      • ‘These were in the following: lambda, parietal eminence, asterion, and occipital torus.’
    4. 1.4Biochemistry as modifier Denoting one of the two types of light polypeptide chain present in all immunoglobulin molecules (the other being kappa).
      • ‘As in most reported cases of CDS + B-CLL cells, our patient showed only lambda light chains on the surface of B cells.’
      • ‘In addition, numerous plasmacytoid lymphocytes showed strong cytoplasmic staining for IgM and kappa light chains and negative reaction for lambda light chains.’
      • ‘Immunohistochemical studies revealed lambda light chain restriction in the neoplastic follicles.’
      • ‘Immunohistochemistry is noncontributory, and the granular material may nonspecifically stain positively with a host of antibodies, including immunoglobulin A, IgG, IgM, K light chain, lambda light chain, and complement.’
      • ‘A slight predominance of lambda light chains was recorded.’

  • 1Wavelength.

  • 2Astronomy
    Celestial longitude.

Origin

Greek.

Pronunciation

lambda

/ˈlamdə/