https://www.merriam-webster.com/dictionary/ad
網頁The meaning of AD is advertisement. How to use ad in a sentence. Noun (1) by shortening Noun (2) by shortening Prefix borrowed from Latin, prefix forming verbs and verbal derivatives, marking movement toward, tendency, addition, from ad, preposition, "to, as far as, at, near, in accordance with" — more at at entry 1 ...