1. plural of irrationality; instances or qualities of being irrational; lack of reason or logic
Usage: countable noun; often used in academic, philosophical, or psychological contexts
2. in mathematics, irrational numbers; numbers that cannot be expressed as a simple fraction
Usage: technical; used in mathematics education

Examples

• The irrationalities in his argument made it difficult to take his position seriously.
• Fear often leads to irrationalities in human decision-making.
• Economists study the irrationalities that cause people to make poor financial choices.
• The irrationalities of the market sometimes defy explanation.
• In mathematics class, we learned that pi and the square root of 2 are irrationalities.
• Her irrationalities became more apparent as the debate continued.
• The film explores the irrationalities of human behavior during times of crisis.