telephoner

telephone +‎ -er

telephoner (plural telephoners)

1. A person who telephones, especially one who does so for a commercial organization.
   • 1939 December, Railway Magazine, page 404:

         TO CALLERS AND TELEPHONERS
     Consequent on the war and the blackout regulations,
     as an emergency measure to assist the staff in getting
     home before it is fully dark, our office hours (without a
     lunch interval), commencing Monday, November 20,
     and continuing until Saturday, February 10, 1940, will be :
         Mondays to Fridays - 9 a.m. till 3.15 p.m.
         Saturdays - - 9 a.m. till 1 p.m.

• caller