1. sleeveless undershirts or athletic shirts worn close to the body
Usage: primarily British English
2. one-piece tight-fitting garments worn by wrestlers or runners
Usage: sports context
3. individual unpaired electrons in atoms or molecules
Usage: chemistry; physics

Examples

• The athletes wore matching singlets for the wrestling tournament.
• He packed several cotton singlets for his trip to Australia.
• The runners’ singlets displayed their team colors prominently.
• She prefers wearing singlets under her work shirts in summer.
• The chemistry professor explained how singlets affect molecular behavior.
• Olympic wrestlers must wear regulation singlets during competition.