A vocal performance with no instrumental accompaniment.
In a manner of a choir with no instrumental accompaniment; literally, "in the style of the (Sistine) Chapel (in Rome)", such as a musical Mass done a cappella.
Singing solely or mainly without instrumental accompaniment.
Related to a form of purely vocal music mostly associated with American college performance groups.
The sound made by a duck.
A fraudulent healer, especially a bombastic peddler in worthless treatments, a doctor who makes false diagnoses for monetary benefit, or an untrained or poorly trained doctor who uses fraudulent credentials to attract patients
Any similar charlatan or incompetent professional.
Any doctor.
Falsely presented as having medicinal powers.
To make a noise like a duck.
Of a queen bee: to make a high-pitched sound during certain stages of development.
To practice or commit quackery (fraudulent medicine).