Lambdacism vs. Rhotacism — What's the Difference?

(phonology) A pronunciation shift whereby /l/ or other closely related phonemes are substituted for other sounds (typically /r/), as Sally for Sarah or Molly for Mary.

The change of a sound such as (s) or (z) to (r) in the history of a language, such as the change of Proto-Indo-European intervocalic s to r in Latin, resulting in alternations such as that seen between the singular noun genus, "kind, sort" and its plural, genera. Also called rhoticism.

A fault in speaking or in composition, which consists in too frequent use of the letter l, or in doubling it erroneously.

The inability to articulate the (r) sound as a rhotic consonant.

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.

The substitution of the (r) sound with another sound, such as (w), because of this inability.

The use of the sound of l for that of r in pronunciation; lallation; as, Amelican for American.

The articulation of a sound other than (r) as (r), especially the articulation of (z) as (r).

Speech defect involving excessive use or unusual pronunciation of the phoneme `l'

An exaggerated use of the sound of the letter R.

A linguistic phenomenon in which a consonant changes into an R, such as Latin flos becoming florem in the accusative case; rhotacization.

Inability to pronounce the letter R; derhotacization.

An oversounding, or a misuse, of the letter r; specifically (Phylol.), the tendency, exhibited in the Indo-European languages, to change s to r, as wese to were.