noun, plural cross-staffs, cross-staves. Astronomy.
Origin of cross-staff
Examples from the Web for cross-staff
The cross-staff had not then come into use, and it was never of much service in low latitudes.
Even the navigators of the fifteenth century were aware of the deficiencies of the cross-staff and sought to improve upon it.
The simplest and crudest form of measurer of which the record has been preserved is known as the cross-staff.
Iacobs staffean instrument formerly used for measuring the altitude of the sun; a cross-staff.The Fatal Dowry|Philip Massinger
The vane of a cross-staff, made to slide along it by means of a square socket; it may be set to any of the graduations.The Sailor's Word-Book|William Henry Smyth