Back vowel

A back vowel is any in a class of vowel sound used in spoken languages. The defining characteristic of a back vowel is that the highest point of the tongue is positioned relatively back in the mouth without creating a constriction that would be classified as a consonant. Back vowels are sometimes also called dark vowels because they are perceived as sounding darker than the front vowels.[1]

Near-back vowels are essentially a type of back vowels; no language is known to contrast back and near-back vowels based on backness alone.

The category "back vowel" comprises both raised vowels and retracted vowels.