Period means different things.

• Period (punctuation), a punctuation mark, also called a full stop
• period (geology), a series of rock strata, and the time during which the rocks were laid down
• The time every month when a woman menstruates
• The time it takes to finish one sequence of something that happens again and again
  • Orbital period
• Periodic function
• The time it takes to play 1/3 of an ice hockey game
• A row in the periodic table