WordNet (r) 3.0 (2006):

workings
    n 1: the internal mechanism of a device [syn: works,
         workings]
    2: a mine or quarry that is being or has been worked [syn:
       working, workings]

Moby Thesaurus II by Grady Ward, 1.0:

67 Moby Thesaurus words for "workings":
   abysm, abyss, act, acting, action, activism, activity, agency,
   bank, behavior, chasm, clockworks, coal mine, colliery, conduct,
   dig, diggings, direction, doing, drive train, driving, employment,
   excavation, execution, exercise, function, functioning, gear,
   gold mine, gulf, handling, innards, machinery, management,
   manipulation, mechanism, mine, motion, movement, movements,
   occupation, open cut, opencast, operancy, operation, operations,
   performance, performing, pit, play, power train, practice, praxis,
   quarry, responsibility, running, servomechanism, shaft, steering,
   swing, watchworks, well, wheels, wheels within wheels, work,
   working, works