WordWeb Online

1. (often followed by 'to') in the habit of or adapted to
   "accustomed to doing her own work"; "I've grown accustomed to her face"
    
2. Commonly used or practised; usual
   "his accustomed thoroughness"
   - customary, habitual, wonted

1. Make psychologically or physically used (to something)
   - habituate

See also: used to, usual, wont to

Type of: alter, change, modify

Antonym: unaccustomed