Jolan,
I must admit I'd never have got swell. I've only got some tatty old dictionaries (c.1960)and I'm damned if I'll buy any more.
Have you considered using the Urban Dictionary (on the web)as a reference. You could have some really interesting words and phrases to play with.
I think on reflection that inset is clearly WRONG,so Jolan you have fooled all of the people all the time.