1. accustomed. Usual,customary,habitual refer to a settled and constant practice. Usual indicates something that is to be expected by reason of previous experience, which shows it to occur more often than not: There were the usual crowds at the celebration. Something that is customary is in accordance with prevailing usage or individual practice: It is customary to finish up with a bonfire. That which is habitual has become settled or constant as the result of habit on the part of the individual: The merchants wore habitual smiles throughout the season.2. general, prevailing, prevalent, familiar, regular. 3. expected, predictable.
late 14c., from Old French usuel (late 13c.), from Late Latin usualis "ordinary," from Latin usus "custom" (see use). The usual suspects is from a line delivered by Claude Rains (as a French police inspector) in "Casablanca" (1942).