ostiary

[os-tee-er-ee] /ˈɒs tiˌɛr i/
noun, plural ostiaries.
1.
Also called doorkeeper, porter. Roman Catholic Church.
  1. a member of the lowest-ranking of the four minor orders.
  2. the order itself.
    Compare acolyte (def 2), exorcist (def 2), lector (def 2).
2.
a doorkeeper, as of a church.
Origin
1400-50; late Middle English hostiary < Latin ōstiārius doorkeeper, equivalent to ōsti(um) door, entrance (see ostium) + -ārius -ary
British Dictionary definitions for ostiary

ostiary

/ˈɒstɪərɪ/
noun (pl) -aries
1.
(RC Church) another word for porter2 (sense 4)
Word Origin
C15: from Latin ostiārius doorkeeper, from ostium door