汚
オ, けが.す, けが.れる, けが.らわしい, よご.す, よご.れる, きたな.い
dirty, pollute, disgrace, rape, defile
JLPT2 G7 S6 F908
The relevant seal inscription form is 于# (U-shaped) + 水 water → U-shaped puddle → *dirty*; *filthy* (← stagnant water) → *soil*; *corrupt*; *disgrace*; *taint* → *impure*; *mean*; *base* → *rape*.
[Full Kanji Etymology List]