solemn
/ˈsä-ləm/
adjective
very serious or formal: such as
characterized by or causing a very serious and subdued attitude or atmosphere
done or made with the utmost sincerity
a solemn gathering
noun
a mass marked by the use of incense and by the presence of a deacon and a subdeacon in attendance on the celebrant
noun
an absolute and irrevocable public vow taken by a religious in the Roman Catholic Church under which ownership of property by the individual is prohibited and marriage is invalid under canon law