Definition of lambda in US English:



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

    • ‘The cosmological constant, which Einstein signified by the Greek letter lambda, made it so.’
    • ‘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.’
    • ‘Clearest are the differences between alphas, epsilons, and lambdas.’
    • ‘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.’
    • ‘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’
      • ‘Evidence that PP may play a dominant role in UV-induced transition mutagenesis has been obtained for bacteria and lambda phage.’
      • ‘The second class of vectors are derived from the bacteriophage (bacterial virus) lambda.’
      • ‘The diagram below at right shows a virus that attacks bacteria, known as the lambda bacteriophage, which measures roughly 200 nanometers.’
      • ‘The sequence of the lambda and phiX174 bacteriophages9 provided the initial confidence booster for undertaking this project.’
      • ‘Also, it is the surface receptor of the virus, bacteriophage lambda.’
    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).
      • ‘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.’
      • ‘In addition, numerous plasmacytoid lymphocytes showed strong cytoplasmic staining for IgM and kappa light chains and negative reaction for lambda light chains.’
      • ‘As in most reported cases of CDS + B-CLL cells, our patient showed only lambda light chains on the surface of B cells.’
      • ‘Immunohistochemical studies revealed lambda light chain restriction in the neoplastic follicles.’

  • 1Wavelength.

  • 2Astronomy
    Celestial longitude.