monoisotopic mass

https://doi.org/10.1351/goldbook.12495
Exact mass of an ion or molecule calculated using the mass of the most abundant isotope of each element.
See also: accurate mass
Source:
PAC, 2013, 85, 1515. (Definitions of terms relating to mass spectrometry (IUPAC Recommendations 2013)) on page 1569 [Terms] [Paper]