Lambdacism

Definition:

(n.) A fault in speaking or in composition, which consists in too frequent use of the letter l, or in doubling it erroneously.
(n.) 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.
(n.) The use of the sound of l for that of r in pronunciation; lallation; as, Amelican for American.

Compare lambdacism with other words:

iotacism vs. lambdacism