noun, plural or·thos·ta·tai [awr-thos-tuh-tahy] /ɔrˈθɒs təˌtaɪ/.
Examples from the Web for orthostates
This is unlikely because the floor level would then have been above the base of the orthostates.
They are firmly founded on the rock and reach up nearly to the base of the orthostates.
The are interior walls on either side of a door which in the Erechtheum reached up only five courses above the orthostates.