n. An element meaning ‘thousand,’ also used for ‘a thousandth part,’ especially in words relating to physics: as, millimeter (the thousandth part of a meter).
Word Usage
"An FSH level above 30 (in units called milli-international units per milliliter), as measured in a blood test on any of the first six days of a woman's period, is the most reliable indication that she is in perimenopause."