pentecoster

From pentecost +‎ -er, from Medieval Latin pentēcostē, from Ancient Greek πεντηκοστή (pentēkostḗ, “fiftieth”). Cognate with Pentecost.

pentecoster (plural pentecosters)

1. An officer who commands fifty men, particularly (historical) in the Spartan army.
   • 1784-1810, William Mitford, The History of Greece:

     ...they would have the command of the pentecoster, penteconter, or pentecoptater (for thus variously the title is written)...

• quinquagenarian, quinquagenary (obsolete)

• “pentecoster”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.