A British term to describe that something is good or went well; derived from Irish immigrants term: "Is maith sinn" or "'s maith sinn", pronounced: "Is mah shin" or "Smah shin", meaning: "that is good"
Englishman: That is smashing!
Woman: haha! cute word! what does it mean?
Englishman: Smashing...
Woman: I still dont get it...
Englishman: It means...smashing