Related Clues:

• To benefit Mother, there's nothing casual to a half-century
• Nothing casual for her before fifty
• Perhaps like dance in support of mall early closing
• Academic event: time for the glad rags
• A learner joins class that's strict
• Conventional - ceremonious
• Precise - ceremonial
• Official - conventional
• Ceremonial or official
• Class A pill at last is reserved
• Stiff examination involving mark set by female
• Bench taking a line that's rather stiff
• Official; stiff
• Precise class a student attends
• Get into a queue? It's required by rule