The term "oily-tongued" is often used to describe someone who is insincere or excessively flattering. However, there are several other synonyms that can be used to convey a similar meaning. One alternative term is "smooth-talking," which is often used to describe someone who has a way with words and is able to charm others with ease. Another synonym for "oily-tongued" is "honey-tongued," which refers to someone who speaks in a sweet, persuasive manner. Other synonyms include "silver-tongued," "glib-tongued," and "fluent-tongued." No matter which synonym is used, the intended meaning is clear - someone who uses persuasive language in order to gain an advantage over others.