macrometer in English dictionary macrometer Meanings and definitions of "macrometer" An instrument for determining the size or distance of inaccessible objects by means of two reflectors on a common sextant. noun An instrument for determining the size or distance of inaccessible objects by means of two reflectors on a common sextant. more Grammar and declension of macrometer macrometer (plural macrometers) more Sample sentences with "macrometer" Declension Stem Try again Available translations Persian Tamil Authors