Definition of geotectonics in US English:

geotectonics

noun

Geology
  • With singular concord. = "tectonics".

Origin

Mid 19th century. From geo- + tectonics, after German Geotektonik.

Pronunciation

geotectonics

/ˌdʒiːə(ʊ)tɛkˈtɒnɪks/