Micrograms are units of measurement used in the scientific world to describe very small amounts of substances. Synonyms for micrograms include μg, mcg, and ug which are all abbreviations for the term microgram. Additionally, the word microgram may be replaced with the term micromole which is used to describe the concentration of a substance in a sample. Other synonyms for micrograms include nanograms (ng) and picograms (pg) which are smaller units of measurement than micrograms. No matter which term is used, it is important to use the correct unit of measurement when describing substances accurately in research or medical settings.