
Noah Webster
Semi-diameter
SEMI-DIAM'ETER, noun [semi and diameter.] Half the diameter; a right line or the length of a right line drawn from the center or sphere to its circumference or periphery; a radius.

SEMI-DIAM'ETER, noun [semi and diameter.] Half the diameter; a right line or the length of a right line drawn from the center or sphere to its circumference or periphery; a radius.