IPA: /ˈsɪr.i.əs.nəs/
KK: /ˈsɪr.i.əs.nəs/
A state of being earnest or thoughtful, often indicating importance or gravity.
The seriousness of the situation made everyone quiet and attentive.
Seriousness → It is formed from "serious" (from Latin *serius*, meaning grave or important) and "-ness" (a suffix meaning the state or quality of). The word "seriousness" refers to the state of being serious or the quality of being grave or important.
Think of the word 'serious' meaning grave or important, and remember that 'seriousness' is the quality of being serious.