It is difficult to explain as it can apply slightly differently depending on the situation. If I said a person was glib I would mean they are a "smooth-talker." For example, if somebody knows all the answers and the answers are too perfect I might say they are glib. If somebody was in trouble and they came up with a good excuse very quickly I might say they are glib. If a boy tried to pick up a girl and was flattering her in a clever way I might say he was glib. The word glib is not used a lot. In addition, it is not meant in a positive way. You would use it in a negative way. I hope this helps.

It's not a commonly used word, but people may talk about a glib salesman or a glib politician. It means to talk articulately and persuasively, but without much substance or indeed deceitfully.

Wow, that's a word I haven't heard in a while. It's really not surprising that Benjamin has used the word glib before. I don't think I've ever used it in real conversation before. But, I have seen it used once or twice. Glib is used most often to describe a smooth talker who uses lots of fancy words. Politicians seemed to come to mind when I hear the word. "American politicians will will say anything to appeal to voters, so they become excellent in regards to glibness, wordplay, and beating around the bush." "The glib car salesman had me signing the dotted line in no time at all!"

I am a native English speaker and have never used the word "glib" in my life. Sorry I couldn't be of more help!