IPA: //baɪˈdɛntəl//
KK: /bɪˈdɛntəl/
Describing a sound or speech sound that is produced using both the upper and lower teeth.
The letter 'f' is bidental because it is made with both the upper and lower teeth touching the lip.
Bidental is formed from "bi-" (meaning two) and "dentalis" (from Latin "dens," meaning tooth). The word refers to something that has two teeth or is related to two dental structures.
Think of 'bi-' meaning two and 'dental' relating to teeth — that's why bidental refers to something with two teeth.