noun the use of the sound of l for that of r in pronunciation; lallation; as, amelican for american.
2. lambdacism ·noun a fault in speaking or in composition, which consists in too frequent use of the letter l, or in doubling it erroneously.
3. lambdacism ·noun 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.