No, it's not a bad word (: Sometimes it's considered rude, especially when children use it. The more polite form would be "It stinks". Other variations include "This/that stinks!" and "You stink!" All of these are casual language, very informal. Basically it means that someone or something (a situation) is bad or a negative. While a speaker could literally be saying someone or something smells bad, as slang it is more often used as above. Example : A) "My car's in the shop right now." B) "Oh no! What happened? Are you all right?" A) "Yea, I'm fine but my car's not. It's going to cost be a grand to fix!" B) "Wow. That really sucks.' Speaker B is sympathetic towards Speaker A and agreeing that those are unfortunate circumstances.

Good question! It is impolite but not vulgar. If a very young child said "it sucks" you would think it rude. If an adult said "it sucks", it would be acceptable in most informal settings, but only really if you weren't talking about something that would not offend the person you are with. For example, if someone played you their new song on the guitar and asked what you thought of it, "it sucks" would be rude, and probably hurt their feelings, although it is still not a vulgar expression.

Nancy: Your other respondents are poorly informed. "sucks" refers to a person performing oral sex upon another person. Thus, the word has an origin that is considered by some "dirty". So to say that a person "sucks" is to suggest that they engage in ora-genital contact. Today, people commonly refer to just about anything they do not like as something that "sucks". Any event can be said to "suck". the usage has become so common, that even the people who respond to you have no awareness of the origin of the word. When people are hostile to each other, it is not uncommon for them to say something like; "Bite me!" or "Eat me!" or "Suck me!" or something like that. Thus, it has an explicit sexual origin. (Sorry to bother you with a private message, but I did not feel comfortable writing this in the public forum. It might have been censored anyway)

Basically, it is a "bad" work, but it has come into common usage.

Bad*