Discover what PS means in English, how to use it in letters and emails, plus examples and tips for correct usage. Using the full form of PS — Postscript — sounds abrupt in a letter and is therefore used as PS or P.S . in short. What Is the Meaning of PS ? PS means postscript, which is derived from the Latin word, Postscriptum. The word postscript means “written after”. Explore the full form of PS , its meaning, usage, and how to add it in different forms of written communication. The full form of PS is Postscript. PS is a further thought that was incorporated into a document or letter after writing and signing the document or letter, probably at the end.