1. Occurring ever half hour

1. Every thirty minutes, every half hour

See also: periodic, periodical

• pretorian
• pretorium
• pretrial
• pretrial conference
• prettify
• prettily
• prettiness
• pretty
• pretty much
• pretty up
• pretty-pretty
• pretzel
• Preussen
• Prevacid
• prevail
• prevailing
• prevailing party
• prevailing westerly
• prevailing wind
• prevalence
• prevalent
• prevaricate
• prevarication
• prevaricator
• prevenient