1. Every fourth year, of 366 days; so called as, by adding a day to February, making the days thereafter leap forward one more than usual.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• keap year,
• peap year,
• oeap year,
• lwap year,
• lsap year,
• ldap year,
• lrap year,
• l4ap year,
• l3ap year,
• lezp year,
• lesp year,
• lewp year,
• leqp year,
• leao year,
• leal year,
• lea- year,
• lea0 year,
• leap tear,
• leap gear,
• leap hear

The adjective form of the word "leap year" is "leap-year".

The plural form of the word "leap year" is "leap years".

The singular form of the word "leap year" is "leap year".