The phrase "tropical years" refers to the amount of time it takes for the Earth to complete one revolution around the sun, based on the position of the Earth's seasonal changes in relation to the sun. Synonyms for this term could include "solar years," "equinoctial years," or "annual orbital cycles". Additionally, "tropical revolution" or simply "orbit cycle" could also be used in place of "tropical years". Whatever the term used, it refers to a key component of the Earth's overall orbit, allowing for regular patterns of seasonal changes and ultimately supporting life on our planet.