Here is a list of some common – and some obscure – abbreviations and their meanings.

Some of them are so outdated you’ll rarely see them, but those are likely the ones which will surprise you one day, and leave you in the dark.

• B.A. (or sometimes written A.B.) – Bachelor of Arts
• Abbr. – abbreviated
• A.C. – before Christ
• Acct. – account
• Ad. lib. – at pleasure (Latin: ad libitum)
• Adv. – advocate, or adverb
• Ald. – alderman
• Amb – ambassador
• Anon. – anonymous
• Apoc. – apocalypse
• Bbl. – barrel
• C. – one hundred (roman numeral)
• C.E. – Civil engineer
• Co. – company, or county
• C.O.D – cash (or collect) on delivery
• Col. – Colonel
• Cr. – credit
• Cwt. – Hundred weight
• D. – five hundred (roman numeral)
• D.D. – Doctor of Divinity
• Dea. – Deacon
• Dep. – deputy
• Dept. – department
• Dict. – dictator, dictionary
• Do. – ditto
• Ed. – editor, edition
• E.E. – errors expected
• Etc. or &c. – etcetera, and so on.
• Gen. – genesis, or general
• Govt. – government
• Hon. – honourable
• Hun. – hundred
• I.H.S – Jesus the Savior of Men
• Incog. – incognito, unknown
• Incor. or Inc. – incorporated
• I.O.U. – I owe you
• L – fifty (roman numeral)
• Lb. – pound
• Lib. – book, library
• Lieut. – Lieutenant
• Lit. – literature, or literally
• LL.D. – Doctor of Laws
• M. – a thousand (roman numerals)
• M.A. – master of arts
• M.C. – Member of congress
• M.D. – Doctor of Medicine
• Mem. – memorandum, memento
• Messrs. – gentlemen (French: messieurs)
• Met. – metaphysics
• Metr. or Metro. – metropolitan
• M.M. – two thousand (roman numerals)
• Mme. – Madame
• M.P. – Member of Parliament, or Methodist Protestant
• Mr. – Mister
• Mrs. – Mistress
• Ms. – Miss, or manuscript
• No. or Nos. – number or numbers
• Non Seq. – Non-sequiter, it doesn’t not follow
• N.T – new testament
• Obj. – object
• Obs. – obsolete, observatory
• O.S. – old style (before 1752)
• Oz. – ounces
• Phys. – physician
• Pl. – plural
• P.O. – post office
• Prot. – protestant
• Pro Tem. – for the time (Latin)
• Prov. – proverbs, or provincial
• P.S. – Postscript
• Ps. – psalm
• Pt. – part, pint, payment or port
• Pub. – publisher or public
• Qr. – quarter
• Qt. – Quart
• R. – take (from recipe)
• R.S.V.P. – please respond (from French: repondez, s’il vous plait)
• Scan. Mag. – great scandal!
• Sec. – secretary, second, or section
• Sen. – Senator, senate, or senior
• Seq. – following (sequential)
• St. – saint, street or strait
• Sup. – supplement or superior
• Ter. – territory