Main definitions of lac in English

: lac1lac2lac3

lac1

noun

  • A resinous substance secreted as a protective covering by the lac insect, used to make varnish, shellac, sealing wax, dyes, etc.

    lacquer, shellac, japan, enamel, glaze, polish, oil, resin, wax
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Origin

Late Middle English: from medieval Latin lac, lac(c)a, from Portuguese laca, based on Hindi lākh or Persian lāk.

Pronunciation

lac

/læk//lak/

Main definitions of lac in English

: lac1lac2lac3

lac2

adjective

Biology
  • attributive Denoting the ability of normal strains of the bacterium "E. coli" to metabolize lactose, or the genetic factors involved in this ability (which is lost in some mutant strains).

    • ‘Other events are correlated with the stable exploration of new niches, like the acquisition of the lac operon by E. coli or pathogenicity islands by Salmonella.’
    • ‘This system is probably still the best-understood regulatory system in eukaryotic biology and today is taught in every textbook of genetics and cell biology, alongside the lysis-lysogeny decision of and the lac operon of E. coli.’
    • ‘These strains might not even use their lac gene products to metabolize lactose.’
    • ‘In addition to the lac operon, a number of other synthetic and natural genetic circuits have been analyzed for robustness and evolvability.’
    • ‘A metabolite of lactose binds to the lac repressor, changing the protein's shape and thereby causing it to loosen its grip on the DNA.’

Origin

1940s: abbreviation of lactose.

Pronunciation

lac

/læk//lak/

Main definitions of lac in English

: lac1lac2lac3

lac3

noun

  • variant spelling of lakh

Pronunciation

lac

/læk//lak/