system of cantillation marks and their music, which are used to chant sacred books; there are trop systems for Torah, haftarah, Lamentations, and the megillot.

or tropo - a term used to refer to tropospheric ducting. Similar to skip and eskip...the troposphere's condition are right that signals can bounce off of it. Usually when trop occurs, signals that are within 100-200 miles come in or come in better than usual.

turning towards (_Heliotropium_ = "turning towards the sun") (also can refer to a keel)

Tropopause