Definition of unstep in US English:

unstep

verbunstepping, unstepped, unsteps

[with object]Nautical
  • Remove (a vessel's mast) from its step.

    • ‘Masts which are only slightly over the minimum bridge clearance might conceivably be arranged with removable upper sections which could be unstepped with the aid of a crane.’
    • ‘If the mast was not unstepped, sailboat owners should check the halyards.’

Pronunciation

unstep

/ˌənˈstep/