tectonic

1 ENTRIES FOUND:
tectonic /tɛkˈtɑːnɪk/ adjective
tectonic
/tɛkˈtɑːnɪk/
adjective
Britannica Dictionary definition of TECTONIC
always used before a noun
1 
geology : of or relating to changes in the structure of the Earth's surface
2 
: having a large and important effect