be set in (one's) ways(redirected from be set in their ways)
be set in (one's) ways
To be habituated to one's routine or usual behavior, often to the point of being unwilling to change any aspect of it. Grandma will never retire—she's been a teacher for 50 years and is totally set in her ways. You'll never convince him to change, he's too set in his ways now.
set in one's ways, be
Be inflexible, fixed in one's habits, as in She's too set in her ways to go out and buy a dog. This idiom uses set in the sense of "in a rigid position," a usage dating from about 1300.
See also: set