1. plural of foolishness; instances or examples of lack of good sense or judgment
Usage: countable plural form; often used to refer to multiple foolish acts or behaviors
2. the quality or state of being foolish; lack of good sense or judgment (uncountable sense, plural form used for emphasis or in formal contexts)
Usage: less common usage; typically foolishness is uncountable

Examples

• The foolishnesses of youth often lead to regrettable decisions.
• He dismissed their foolishnesses as mere youthful indiscretion.
• The report documented numerous foolishnesses in the company's management.
• Despite repeated foolishnesses, she remained optimistic about the future.
• Their foolishnesses cost them dearly in the end.
• The novel explores the foolishnesses that drive human conflict.