Rude, Rudeness, Impoliteness, Excuse Me
noun, な adjective, verbal noun
When you do something that's your fault and then you say "thanks" after you do it, that's super-duper rude, wouldn't you say? Imagine doing something like this and then thinking to yourself after... wow, I was really rude. This is also often used to mean excuse me, typically followed by ですが or します. Occasionally, it’s also used just on its own, usually when the speaker holds a higher or equal status to the person being spoken to. This particular usage is more prevalent among older generations and is commonly associated with masculine speech.
しつれい
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
なんて失礼な男だ。
Such a rude man.
失礼ですが、年はいくつですか？
Excuse me if this is impolite, but how old are you?
では、お先に失礼します。
I'll excuse myself before you then.