To Get Dirty, To Get Polluted, To Become Dirty
intransitive verb, ichidan verb
Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means dirty so the verb vocab version is to get dirty. You know you're not doing the dirtying, because it's rare (れる) for you to get anything dirty, though things do get dirty on their own.
よごれる, けがれる
Things seem to get dirty easily around here, which is why you go (よご) to great lengths to keep things clean. Note that the reading よごれる is generally used for getting physically dirty, whereas けがれる is more figurative, so more like “to be defiled”.
汚れやすいので白いコントローラーはお勧めしません。
I don’t recommend white controllers because they get dirty easily.
血で汚れたシーツや服は、すぐにオキシドールで洗えば綺麗になるよ。
You can remove blood stains from linen and clothing by washing them right away in hydrogen peroxide.
知らないの？汚れた天使は、もう天界にはいられないんだよ。
Didn't you know? Defiled angels can't stay in the heavenly realm.