antiform

anti- +‎ form

antiform (plural antiforms)

1. (geology) A topographic feature which is composed of sedimentary layers in a convex formation, but may not actually form a real anticline (i.e., the oldest rocks may not be exposed in the middle).
2. (art) A form that defies the usual conventions of artistic forms.
   • 1983, Edith Kurzweil, William Phillips, Writers and Politics: A Partisan Review Reader, page 236:

     Dada forms and antiforms were used as a means of reacting against Abstract Expressionism and abstract art generally […]

• (antonym(s) of “geology”): synform

• (geology): anticline

• Fairmont, natiform