Common Latin Abbreviations Used in English

In this list of common Latin abbreviations you'll find what they stand for and how they're used. The first list is alphabetical, but the definitions that follow are linked thematically. For instance, p.m. follows a.m. 

A.D.

A.D. stands for Anno Domini 'in the year of our Lord' and refers to events after the birth of Christ. It is used as part of a pair with B.C. Here is an example:

• The standard date given for the fall of Rome is A.D. 476. The start date of Rome is, traditionally, 753 B.C. More politically correct are the terms C.E. for the current era and B.C.E. for the other.

A.D. traditionally precedes the date, but this is changing.

A.M.

A.M. stands for ante meridiem and is sometimes abbreviated a.m. or am. A.M. means before noon and refers to morning. It starts just after midnight.

P.M.

P.M. stands for post meridiem and is sometimes abbreviated p.m. or pm. P.M. refers to afternoon and evening. P.M. starts just after noon.

Etc.

The very familiar Latin abbreviation etc. stands for et cetera 'and the rest' or 'and so forth'. In English, we use the word etcetera or et cetera without necessarily being aware it is actually Latin.

E.G.

If you want to say 'for example,' you would use 'e.g.' Here is an example:

• Some of the Julio-Claudian emperors, e.g., Caligula, were said to be insane.

I.E.

If you want to say 'that is,' you would use 'i.e.' Here is an example:

• The last of the Julio-Claudians, i.e., Nero....

In Citations

Ibid

Ibid., from ibidem means 'the same' or 'in the same place.' You would use ibid. to refer to the same author and work (e.g., book, html page, or journal article) as the one immediately preceding.

Op. Cit.

Op. cit. comes from the Latin opus citatum or opere citato 'work cited.' Op. cit. is used when ibid. is inappropriate because the immediately preceding work is not the same. You would only use op. cit. if you have already cited the work in question.

Et Seq.

To refer to a certain page or passage and those that follow it, you may find the abbreviation 'et seq.' This abbreviation ends in a period. 

Sc.

The abbreviation sc. or scil. means 'namely'. Wikipedia says it is in the process of being replaced by i.e.

Latin Abbreviations of Comparison q.v. and c.f.

You would use q.v. if you wanted to make reference to something elsewhere in your paper; while
c.f. would be more appropriate for a comparison with an outside work.