[n] the trait of being serious; "a lack of solemnity is not necessarily a lack of seriousness"- Robert Rice
[n] a quality of naturalness and simplicity; "the simple sincerity of folk songs"
[n] the quality of being open and truthful; not deceitful or hypocritical; "his sincerity inspired belief"; "they demanded some proof of my sincerity"
[n] an earnest and sincere feeling