蔭口(かげぐち)

backbiting; speaking ill of someone behind their back

蔭日向(かげひなた)

in public and private; openly and secretly

蔭干(かげぼ)し

drying in the shade

蔭(かげ)る

to become shaded; to darken

蔭(かげ)ながら

quietly; from behind the scenes

蔭(かげ)の功労者(こうろうしゃ)

unsung contributor

蔭(かげ)の立役者(たてやくしゃ)

behind-the-scenes key player

蔭(かげ)ながら応援(おうえん)しています。

I am quietly supporting you from the sidelines.

人(ひと)の蔭口(かげぐち)は聞(き)きたくない。

I don't want to hear people gossiping.