Approximant

Approximants are speech sounds that involve the articulators approaching each other but not narrowly enough[1] nor with enough articulatory precision[2] to create turbulent airflow. Therefore, approximants fall between fricatives, which do produce a turbulent airstream, and vowels, which produce no turbulence.[3] This class is composed of sounds like [ɹ] (as in rest) and semivowels like [j] and [w] (as in yes and west, respectively), as well as lateral approximants like [l] (as in less).[4]