Галитоз is a medical term that means “bad breath.” You may recognize it as meaning the same thing as the English word halitosis. When Russians borrows words based on Latin and Greek roots or words, they usually remove any grammatical ending from the word. Other examples:

Normally when Russians talk about bad breath, they don't use the medical term. Even educated native speakers might not know it. Instead they say «У него плохо пахнет изо рта», which in a word for word paraphrase comes out “At him it smells bad from the mouth.” Sample sentences:

My favorite bad breath phrase in Russian is «У меня во рту как будто эскадрон ночевал» “It's like an [entire] company [of cavalry] spent the night in my mouth.” But that's not the only one. The Russians love to play with language, and they can get quite creative when describing bad breath, for instance…

Warning! The following example contains English vulgarity and русский мат!

There are a lot of versions of this phrase that vary in their degree of nastiness. I was curious which one was the most common, so I googled them all and came up with this hit count (15 May 2009):

Versions 1 and 2 are kiddie talk. Adults may use them to avoid obscenity. #3 uses a fairly neutral word but still gets the point across. 4 and 5 are obscene. Do NOT use them in front of your instructors in Moscow or in front of your host mother.