From skābs (“sour, acid”) + -ums. In the 1850s, K. Valdemārs tried to use skābums in the sense of “acid (chemical substance),” but without success: skābe, which already existed at the time, became the standard term for this sense.
skābums m (1st declension)
- sourness, acidity (the quality of that which is sour, acid in taste (but also in smell); a substance with acidic properties)
šķīduma skābums ― solution acidity
kuņģa sulas skābums ― the acidity of gastric juice
nevarēju saprast, vai viņam tā šķobīt seju lika ogu skābums vai pēkšņa smieklu lēkme ― I couldn't understand if it was the sourness of the berries or the sudden laughter that made his face (look) so shaken
augsnes skābums rodas galvenokārt dažādu mikrobioloģisku procesu rezultātā ― the acidity of the soil is a result of several microbiological processes
mucām līdzi no pagraba atnākusi skābuma un pelējuma smaka ― together with the barrels from the cellar came a smell of sourness and mold