diapir

noun

di·​a·​pir ˈdī-ə-ˌpir 

: an anticlinal fold in which a mobile core has broken through brittle overlying rocks

diapiric

ˌdī-ə-ˈpir-ik 

adjective

Word History

Etymology

French, probably from Greek diapeirein to drive through, from dia- + peirein to pierce; akin to Greek poros passage — more at fare

First Known Use

1918, in the meaning defined above