unhitch

un- +‎ hitch

unhitch (third-person singular simple present unhitches, present participle unhitching, simple past and past participle unhitched)

1. To disconnect; to detach; to undo that which is hitched.
   • [1877], Anna Sewell, “A Strike for Liberty”, in Black Beauty: […], London: Jarrold and Sons, […], →OCLC, part II, pages 106–107:

     There is no knowing what further mischief she might have done, had not York promptly sat himself down flat on her head, to prevent her struggling, at the same time calling out, "Unbuckle the black horse! run for the winch and unscrew the carriage pole; cut the trace here—somebody, if you can't unhitch it."

   • 2022 January 12, Benedict le Vay, “The heroes of Soham...”, in RAIL, number 948, page 43:

     Yet had the whole train and all its bombs gone, had the engine crew merely jumped from the train and run as simple self-preservation would have suggested, or unhitched just the engine to make their escape faster, the whole town would have gone and most of the people with it, leaving just a smoking wasteland. Hundreds would have died.

• Hutchin