: an instrument similar to a cross-staff but fitted with a reflector and formerly used for taking the altitudes of heavenly bodies

Word History


back entry 1 + staff; from the position of the observer, whose back is turned toward the sun when using it

First Known Use

1627, in the meaning defined above

Time Traveler
The first known use of backstaff was in 1627

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Dictionary Entries Near backstaff

Cite this Entry

“Backstaff.” Dictionary, Merriam-Webster, Accessed 6 Dec. 2023.

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