noun plural but singular in construction
1. : a theory that the lithosphere of the earth is divided into a small number of plates which float on and travel independently over the mantle and that much of the earth's seismic activity occurs at the boundaries of these plates as a result of frictional interaction
2. : the process and dynamics of tectonic plate movement ; also : a similar process on a planet other than the earth
• plate-tectonic ¦ ̷ ̷ ˌ ̷ ̷ ¦ ̷ ̷ ̷ ̷ adjective