enter or assume a certain state or condition; "He became annoyed when he heard the bad news"; "It must be getting more serious"; "her face went red with anger"; "She went into ecstasy"; "Get going!"
come into existence; "What becomes has duration"
undergo a change or development; "The water turned into ice"; "Her former friend became her worst enemy"; "He turned traitor"
the period of time that it takes for a planet (as, e.g., Earth or Mars) to make a complete revolution around the sun; "a Martian year takes 687 of our days"
a period of time containing 365 (or 366) days; "she is 4 years old"; "in the year 1920"
a period of time occupying a regular part of a calendar year that is used for some particular activity; "a school year"