tropical year

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. See solar year.

Wiktionary

1. n. The time that it takes for the Sun to return to the same position along the ecliptic, as viewed from the Earth, especially:
2. n. A vernal equinox year, the time between two successive vernal equinoxes.

GNU Webster's 1913

1. n. See under Tropical.

WordNet 3.0

1. n. the time for the earth to make one revolution around the sun, measured between two vernal equinoxes