noun
Meaning
(phonetics) Any sound articulated with the tongue near or touching the back of the alveolar ridge.
“The sibilant postalveolars (i.e. fricatives and affricates) are sometimes called ‘hush consonants’ because they include the sound /ʃ/ of English ‘Shhh!’ (as distinguished from the ‘hiss’ consonant /s/, as in ‘Ssss!’).”
postalveolarpost-alveolar consonantpostalveolar consonant