Humble Japanese
Humble Language
noun
Language when you defer to modesty is humble Japanese. Of course, this doesn't have to refer to Japanese, though it usually does, meaning this could mean humble language as well.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
どうしてそれが謙譲語だと思ったんですか。
What made you assume that it was humble Japanese?