opishet
Opishet is a term that appears to be a misspelling or a less common variation of "opisthos". Opisthos, in biological and anatomical contexts, generally refers to the rear or posterior part of an organism or structure. For instance, in zoology, it might describe the tail end of an animal. In botany, it could refer to the back of a leaf or flower.
The specific usage of "opishet" is unclear without further context. It is possible it is a neologism,