gunter rig
noun
variants or less commonly gunter
plural -s
: a rig used on a small sailing boat consisting of an upper mast stepped in a gunter iron and moved up or down on a lower mast and supporting a yard to which is laced a triangular sail
called also sliding gunter
Word History
Etymology
after Edmund Gunter †1626 English mathematician; from its resemblance to an instrument used in making mathematical calculations according to a system devised by Gunter