カス in the context of 俺はやる lyrics by Wanyudo

Question

I can't figure out the meaning of the chorus from the song 俺はやる by Wanyudo. Particularly I have a problem with the word カス.

The context is as follows (someone transcribed the full lyrics here, the link contains also a live performance of this song without the need for Spotify account):

口だけのカス朽ち果てろよ
こんな奴が相手じゃ誰も付き合えんよな
期待を裏切り嘘をつき人の道に背き
偽善者の人見知り繁華街のごろつき
...
俺はやる やりたいやらなくちゃそれはカス
俺はやる 必ず俺はやる声枯らす
俺はやる やりたいやらなくちゃそれはカス
俺はやる 必ず俺はやる声枯らす

From the first phrase (口だけのカス) I guess カス is a noun and it might be used in the fifth meaning here: dregs (e.g. of society); scum; dross (and etymologically coming from カストリ文化) for someone who lives only from "their mouth", i.e. this rapper.

I imagine the first line (口だけのカス朽ち果てろよ) is something that he hears (from imperative form of 朽ち果てろ) and the meaning of what follows and the chorus would be an answer to it - something like "this is how I live, this is the way of カス."

Is my interpretation correct?

Answer 1

口だけ(の/だ) is a phrase used to mean "all talk", as in someone who talks big, but doesn't ever do anything they say they will.

So 口だけのカス means "pieces of s**t who are all talk".