1. The two imaginary lines around the Earth at approximately 23.5 degrees north and 23.5 degrees south of the equator?.
2. Each of two corresponding circles on the celestial sphere where the sun appears to turn after reaching its greatest declination, marking the northern and southern limits of the ecliptic.
3. Etymology: from Middle English tropik, from Old French tropique, from Late Latin tropicus, from Latin, tropicus, "pertaining to a turn", from Greek tropikos, "of or pertaining to a turn" or "change of a turn".

1. Of or pertaining to a difference of one beta particle in the nucleus of an atom.
2. Designating either of two atoms, one of which has been formed by the ejection of a beta particle from the nucleus, with an increase of 1 in he nuclear charge.

The parallel line of latitude 23° 27': The Tropic of Capricorn lies south of the equator, the southern boundary of the Torrid Zone, and the most southerly latitude at which the sun can shine directly overhead (at the December solstice).