Origin: Germanic Old English suffix
Seriousness has 4 different meanings across 1 category:
an earnest and sincere feeling
"Her seriousness about the mission made everyone trust her immediately."
the quality of arousing fear or distress
"he learned the seriousness of his illness"
the trait of being serious
"a lack of solemnity is not necessarily a lack of seriousness"
The state or quality of being serious.
"The sudden shift in his tone revealed the true seriousness of the situation."