gram
Balance
A balance
Carat is used appropriately to measure the weight of gemstones, as pounds, tons or kilos are used to measure the weight of mass.
It is a meterstick!
The word milligram does not have a synonym. Milligram is a unit that is used to measure the mass of an object.
centimeter
The ten letter word in an Anemometer, unless you are thinking of Wind Vane (which is two words)
mass
It is a measure of the amount of matter in an object.
Micron (one millionth of a meter)
Carat
quire