ˌplanəˈtäləjē noun
( -es -s )
Etymology: planet + -ology (as in cosmology )
: a science that deals with the condensed matter (as the planets and natural satellites) of the solar system
• plan·et·o·log·i·cal -_t ə lˈäjə̇kəl adjective
• plan·et·ol·o·gist -ˈtäləjə̇st noun