形容詞 punctual:

1. acting or arriving or performed exactly at the time appointed

1. Henceforth I expect you to be punctual for meetings.
   我希望你今後準(zhǔn)時到會。
2. He's very punctual always arrives on the dot.
   他很守時--總是按時到。
3. He likes his guests to be punctual.
   他喜歡客人守時。
4. A punctual person always finishes everything ahead of time.
   一個守時的人總是把事情提前做好。
5. We cannot guarantee the punctual arrival of trains in fogy weather.
   霧天我們不能保證火車準(zhǔn)時到達(dá)。
6. Please be punctual in futurity.
   今后請準(zhǔn)時。
7. He is always punctual for appointments.
   他總是準(zhǔn)時赴約。
8. My cat makes a punctual appearance at mealtimes.
   我的貓一到用餐時間就會準(zhǔn)時出現(xiàn)。

punc.tu.al

adj.（形容詞）
Acting or arriving exactly at the time appointed; prompt.
準(zhǔn)時的：精確地在約定的時間行動或到達(dá)；準(zhǔn)時的
Paid or accomplished at or by the appointed time.
如期的：在約定時間或到約定時間為止償還或完成的
Precise; exact.
精確的；確切的
Confined to or having the nature of a point in space.
點的：局限于空間上一點的或具有空間上點的性質(zhì)的

來源：
Middle English [sharp-pointed]
中古英語 [尖的]
from Medieval Latin pônctu3lis
源自 中世紀(jì)拉丁語 pônctu3lis
from Latin pônctum [point] [from neuter past participle of] pungere [to prick] * see pungent
源自 拉丁語 pônctum [點] [] 源自pungere的中性過去分詞 [刺] *參見 pungent

【引伸】
punc.tual.ity
punc.tually
adv.（副詞）