concessive conjunction
A grammatical term for conjunctions that express concession, such as けれども, が, のに, and ても.
"Keredomo" is a typical concessive conjunction.
逆接 is a broader term for adversative or contrastive connection, while 譲歩接続詞 specifically refers to concessive conjunctions that acknowledge a preceding statement before presenting a contrasting one.
Compound of 譲歩 (concession) + 接続詞 (conjunction). A modern grammatical term.