I. -meter /miːtə, mɪtə $ -tər/ AmE suffix [in nouns]
[ Language: French ; Origin: -mètre , from Greek metron 'measure' ]
an instrument for measuring something:
a thermometer (=an instrument for measuring heat)
II. -metre BrE AmE British English , -meter American English /miːtə, mɪtə $ -tər/ suffix [in nouns]
part of a metre, or a number of metres:
a millimetre
a kilometer