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-ary

a suffix occurring originally in loanwords from Classical and Medieval Latin, on adjectives (elementary; honorary; stationary; tributary), personal nouns (actuary; notary; secretary), or nouns denoting objects, especially receptacles or places (library; rosary; glossary). The suffix has the general sense “pertaining to, connected with” the referent named by the base; it is productive in English, sometimes with the additional senses “contributing to,” “for the purpose of,” and usually forming adjectives: complimentary; visionary; revolutionary; inflationary.

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Origin of -ary

Middle English -arie < Latin -ārius, -a, -um; E personal nouns reflect -ārius, objects and places -ārium or -āria; inherited and adopted French forms of this suffix are -er2, -eer, -ier2, -aire; cf. -er1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for -ary

-ary

suffix

(forming adjectives) of; related to; belonging tocautionary; rudimentary
(forming nouns)
  1. a person connected with or engaged inmissionary
  2. a thing relating to; a place forcommentary; aviary

Word Origin for -ary

from Latin -ārius, -āria, -ārium
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for -ary

adjective and noun suffix, in most cases from Latin -arius, -aria, -arium "connected with, pertaining to; the man engaged in," from PIE relational adjective suffix *-yo- "of or belonging to." It appears in words borrowed from Latin in Middle English. In later borrowings from Latin to French, it became -aire and passed into Middle English as -arie, subsequently -ary.

Online Etymology Dictionary, © 2010 Douglas Harper