GNU Collaborative International Dictionary of English

Found one definition

1.       
   ‖Lambda (?), n. [NL., fr. Gr. λάμβδα.]
   1. The name of the Greek letter Λ, λ, corresponding with the English letter L, l.
   
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   2. (Anat.) The point of junction of the sagittal and lambdoid sutures of the skull.
   
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   3. (Phys.) A subatomic particle carrying no charge, having a mass equal to 2183 times that of an electron; it decays rapidly, typically forming a nucleon and a pion. MW10
   
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   Lambda moth (Zool.), a moth so called from a mark on its wings, resembling the Greek letter lambda (Λ).
   
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