現代英漢綜合大辭典postscript
n.
(信末簽名後的)再者, 又及; 附言(略作P.S., PS., PS 或 p.s.)
(書等的)附錄; 跋, 補遺
[英](新聞廣播後的)結束語
現代英漢詞典postscript
n.
（信末簽名後的）又及，附言，再者 (= P.S.)
（書等的）附錄，跋
PS also P.S. American English [countable] postscript
exp. a note written at the end of a letter, adding more information:
She added a PS to say 'hi' to my brother.
Best wishes, Julie. PS Maggie sends her love.
也可以理解為：順帶說壹下