Vac here is a short, casual word for a university holiday — the weeks when there are no classes, between terms. "During the vac" means during the university break.

Vac herevac在這裡 is a short, casual word for a university holiday是大學放假的簡短口語說法 the weeks when there are no classes, between terms也就是學期之間沒有課的那幾週 'During the vac'（during the vac，這樣講） means during the university break意思是大學放假期間

This use is British, and it is narrow: it belongs to students and staff at British universities, especially the older ones like Oxford and Cambridge, where you hear "the long vac" for the long summer break. Outside that world people say "the holidays" or "the break".

This use is British這種用法是英式的 and it is narrow而且範圍很窄 it belongs to students and staff at British universities只屬於英國大學的學生和教職員 especially the older ones like Oxford and Cambridge尤其是牛津、劍橋這類歷史悠久的學校 where you hear 'the long vac'在那裡會聽到'the long vac' for the long summer break指漫長的暑假 Outside that world在那個圈子之外 people say 'the holidays' or 'the break'大家會說'the holidays'或'the break'

It also sounds somewhat dated now; younger students often just say "the break" or "the summer". You will still meet it in novels about university life and in college handbooks.

It also sounds somewhat dated now現在聽起來也有點過時了 younger students often just say年輕學生通常就直接說 'the break' or 'the summer''the break'或'the summer' You will still meet it還是會看到它 in novels about university life and in college handbooks在描寫大學生活的小說和學校手冊裡

Be careful, because the same three letters do other jobs. Vac is also short for vacuum cleaner in British homes — "give the floor a quick vac", and as a verb "I've vacced the stairs". And in American English vacay (not vac) is the casual short form of vacation.

Be careful要小心 because the same three letters do other jobs因為同樣這三個字母還有別的用途 Vac is also short for vacuum cleanervac也是vacuum cleaner（吸塵器）的縮寫 in British homes在英國家庭裡 'give the floor a quick vac'（像'give the floor a quick vac'，用吸塵器快速吸一下地板） and as a verb當動詞用時 'I've vacced the stairs'（像'I've vacced the stairs'，我吸過樓梯了） And in American English而在美式英語裡 vacay (not vac)vacay（不是vac） is the casual short form of vacation才是vacation的口語縮寫

So the same short word points in different directions depending on who is speaking and where.

So the same short word所以同樣這個短字 points in different directions會指向不同的東西 depending on who is speaking and where要看是誰在說、在哪裡說