Not occurring at a regular interval; seldom; not often.
"The train rarely arrives on time during winter storms."
In plain English: Rarely means something happens very seldom, almost never happening at all.
"I rarely eat out because I cook dinner at home most nights."
Usage: Use rarely to indicate that something happens infrequently or almost never, rather than describing the rarity of an object itself. Place it before main verbs but after auxiliary verbs like "do" or "have."
The word rarely is formed by adding the suffix -ly to the adjective rare. It entered English directly from Old French as an adverb meaning "in a rare manner."