In a chat window control click, or right click, the message entry area, go to the spelling section of the menu and deselect "Check spelling as you type".
In a chat window control click, or right click, the message entry area, go to the spelling section of the menu and deselect "Check spelling as you type".
FWIW you can also go to right click -> spelling -> spelling... and change the language. But the choices are somewhat limited, so your language might not be there.
But I feel you. I remember that I was typing in Yahoo Messenger with someone several years ago in romaaji Japanese and phrases like "shitsurei shimasu" (which means approximately "pardon me") would get censored because of the encapsulation of an English vulgarity.