A pleasantry is a polite little thing you say so the talk stays smooth — ‘How are you?’, a light joke about the weather, ‘Lovely to see you’ — not because the content matters much. The word is slightly old-fashioned and a bit formal; you find it in writing and in the plural, pleasantries, more than in casual speech. After they exchanged pleasantries, they got down to business is the classic pattern: first the social noise, then the real subject. It does not mean ‘a pleasant thing’ in general, and it is not quite the same as a joke (a joke is trying to be funny; a pleasantry is trying to be civil). Used with a slight smile, it can even hint that the niceties were empty.

客套話、寒暄（不是「愉快的事」）