正式
Common
I-adj
Noun
Noun
1
adjectival nouns or quasi-adjectives (keiyodoshi)nouns which may take the genitive case particle 'no'noun (common) (futsuumeishi)
formal;official;regular;proper;legal;due (formalities)
彼女の服装は正式なパーティーでは場違いだった。
Her clothes were out of place at a formal party.