From Teflpedia

An approximant (/əˈprɒksəmənt/) is a type of consonant sound produced by bringing one articulator (the tongue or lips) close to another articulator without actually touching it.

Four approximants are found in the standard English phonemes:

Sound IPA Phoneme Place of articulation Example
Voiced palatal approximant /j/ Palatal
Lateral approximant /l/ Lateral
Voiced alveolar approximant /r/ Alveolar
Voiced labio-velar approximant /w/ labio-velar