This is the twelfth of the twenty-four consonant sounds in our British English phonetic chart.
A consonant is a basic speech sound in which the breath is at least partially obstructed and which can be combined with a vowel to form a syllable.
This consonant sound is found in words like mother /mʌðə/, then /ðen/, bathe /beɪð/.
This consonant sound is voiced. It is known as a fricative. Fricatives disrupt the flow of air around parts of the mouth. In this case the air is disrupted by holding the tip of the tongue against the top teeth. Its unvoiced counterpart is /θ/.