Solution

FORMAL

4 clues

Black-tie

Word class: Common adjective
Nature of clue: Description
Difficulty: Easy
Sources: Boatload Puzzles
Topics: Fashion, Traditions

Dressy

Word class: Common adjective
Nature of clue: Synonym
Difficulty: Very easy
Sources: Boatload Puzzles
Topics: Fashion

Official

Word class: Common adjective
Nature of clue: Synonym
Difficulty: Very easy
Sources: Boatload Puzzles

Proper

Word class: Common adjective
Nature of clue: Synonym
Difficulty: Medium
Sources: Boatload Puzzles

Other solutions to Proper

Words are categorized by artificial intelligence: there can be mistakes.