accustom

UK: /əˈkʌstəm/ US: /əˈkʌstəm/ ,(ə kus′təm)

WordReference Random House Learner's Dictionary of American English © 2025

ac•cus•tom /əˈkʌstəm/   v. [~ + object + to + object]

1. to make (something) become familiar by use or habit;
   habituate:

had to accustom themselves to the climate.

WordReference Random House Unabridged Dictionary of American English © 2025

ac•cus•tom  (ə kus′təm), v.t. 

1. to familiarize by custom or use;
   habituate:
   to accustom oneself to cold weather.

• Middle French acoustumer. See ac-, custom
• late Middle English 1425–75

Collins Concise English Dictionary © HarperCollins Publishers::

accustom / əˈkʌstəm/ verb

1. (transitive) usually followed by to: to make (oneself) familiar (with) or used (to), as by practice, habit, or experience

Etymology: 15th Century: from Old French acostumer, from costume custom