1. the quality or state of being conventional; adherence to established customs, standards, or practices
Usage: usually uncountable; formal register
2. a conventional practice, rule, or belief; something accepted by general agreement or tradition
Usage: usually countable in this sense

Examples

• The artist rejected the conventionality of traditional painting techniques.
• Social conventionality often dictates how people dress for formal events.
• Breaking free from conventionality can be both liberating and risky.
• The novel challenged the conventionalities of Victorian society.
• Her unconventional style stood in sharp contrast to the conventionality of her peers.
• The architect's design pushed beyond the conventionality of modern office buildings.