Lateral consonant 边音
A lateral is an L-like consonant, in which the airstream proceeds along the sides of the tongue, but is blocked by the tongue from going through the middle of the mouth.
Most commonly, the tip of the tongue makes contact with the upper teeth (see dental consonant) or the upper gum (the alveolar ridge) just behind the teeth (see alveolar consonant). The most common laterals are approximants and belong to the class of liquids, though lateral fricatives and affricates are common in some parts of the world.