Common words:
* boundary
* dictionary
* factory
* library
* ordinary
* primary
* secondary
* territory
* salary
* military
Less common words:
* auxiliary
* arbitrary
* confectionary
* contradictory
* disciplinary
* elementary
* exemplary
* honorary
* imaginary
* mandatory
* necessary
* parliamentary
* peculiary
* preliminary
* revolutionary
* secretary
* stationary (meaning not moving)
* temporary
* voluntary
Note: While "stationary" (meaning not moving) ends with "ary," it is pronounced differently from "stationery" (meaning writing materials).
This is not an exhaustive list, as there are many other words ending in "ary."