Meaning of counterrotating

coun•ter•ro•tat•ing

Pronunciation: (koun'tur-rō'tā-ting, koun"-), [key]
— adj. Mach.
  1. (of two corresponding or similar moving parts) rotating in opposite directions: counterrotating propellers.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.