‖n. [ NL., fr. Gr. la`mbda. ] 1. The name of the Greek letter Λ, λ, corresponding with the English letter L, l. [ 1913 Webster ]

2. (Anat.) The point of junction of the sagittal and lambdoid sutures of the skull. [ 1913 Webster ]

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 [ PJC ]

Lambda moth (Zool.), a moth so called from a mark on its wings, resembling the Greek letter lambda (Λ). [ 1913 Webster ]

n. [ L. lambdacismus, Gr. &unr_;, fr. la`mbda the letter lambda (Λ). ] 1. A fault in speaking or in composition, which consists in too frequent use of the letter l, or in doubling it erroneously. [ 1913 Webster ]

2. A defect in pronunciation of the letter l when doubled, which consists in giving it a sound as if followed by y, similar to that of the letters lli in billion. [ 1913 Webster ]

3. The use of the sound of l for that of r in pronunciation; lallation; as, Amelican for American. [ 1913 Webster ]