At the moment, I am trying to translate かりゆし58's song "アンマー," which has a lot of expressions in it; I would not be surprised if I misinterpreted some of them. However, the focus for this question is on the meaning of "加減." The kanjis read "addition and subtraction," and that is indeed one of the senses (the word generally means "degree," "moderation"); however, it can also be used as a polite 具合, along with many other senses of the word that do not show up in any dictionary I have looked at. Here is how the word is used in the song (in the video, at (2:25):
アンマーよ 私はアナタに言ってはいけない 決して口にしてはいけない言葉を
加減もせずに 投げつけては アナタの心を踏みにじったのに・・・
Notice the expression 言葉を加減する at the transition of the lines. It shows up on Weblio, but I am still confused on what the expression even means, and how 加減 fits in; in fact, the use of 加減 in most expressions listed on Weblio fails to match what is given on Jisho (or atleast is not clear to me how it matches).
What does 加減 even mean, and what does it mean within the lyrics, specifically in 言葉を加減する?
(EDIT: アンマー is Okinawan Dialect for mother. The song is about how [the vocalist?] disrespected his mother growing up, and is now regretting how much he troubled her, and how throughout his mischief she continued to love him.)