direct case

Short definition from Wiktionary

Noun

1. 1
   A noun case which covers the nominative and possibly other cases such as vocative and/or accusative (the precise definition depends on the case system in question; the term is used especially in simple systems with two or three cases)
2. 2
   A synonym for the nominative case, based on the definition by Peter Edmund Laurent https://books.google.ca/books?id=66NWAAAAcAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q=direct&f=false