A pretext is a false reason you give for doing something, so that the real reason stays hidden. You needed the real motive out of sight, so you offered a respectable one instead. “I only came by to return your book” can be a pretext, if you really came to see who else was in the room. A government may use a pretext — a small insult, a made-up threat — to start something larger. Though actually, pretext is a cooler, more official-sounding word than excuse. An excuse can be small and everyday (“sorry I’m late; the train…”). A pretext often has a feeling of strategy: someone planned the cover story. News writing and serious conversation like this word; children rarely use it. People confuse it with pretense. They sit near each other. A pretext is specifically the fake reason. A pretense is the wider act of pretending. You can have a pretense without a tidy fake reason; a pretext is that fake reason, held up in front like a curtain. The Latin is praetexere, “to weave in front” — a border woven over the cloth, covering what is underneath. That picture still helps.

藉口、託辭（特別指為了掩飾真正目的而編出來的理由）