the shape of a raised edge of a more or less circular object
"The bicycle wheel had a wide, heavy rim to provide extra strength and stability."
the outer part of a wheel to which the tire is attached
"The mechanic tightened the bolts on the rim before mounting the new tire."
An edge around something, especially when circular.
"The doctor examined the patient's eye and noted that the corneal rim was slightly swollen."
A membrane.
In plain English: A rim is the outer edge of something round, like the metal circle that holds a tire onto a wheel.
"The beer foam stayed on the rim until she took her first sip."
Usage: As a noun, rim refers to the raised outer edge or border surrounding an object like a wheel or glass. When used as a verb in informal contexts, it describes licking someone's anus during oral sex.
To form a rim on.
"During their intimate encounter, he gently rimmed his partner to deepen their connection."
To lick the anus of a partner as a sexual act.
In plain English: To rim something means to put liquid around its edge so it doesn't spill over when you drink from it.
"The heavy rain began to rim the windows with water droplets."
The word rim comes from the Old English rima, which originally meant "rim, edge, border, bank, or coast." It traces its roots back to Proto-Germanic rimô and possibly further to a Proto-Indo-European root meaning "to rest" or "support."