Meaning & use
idem
Last updated
Meaning
pronounsingularformalspecialistrare
A scholarly note word meaning the same author or work just cited, so the name need not be repeated.
Grammar: Stands for a previously mentioned author or title inside a note or list; it does not take a normal verb complement like an ordinary pronoun.
Patterns
- idem in a footnote
- cite idem
- idem for the same author
The footnote simply said “idem” to avoid repeating the critic’s name.
After a full citation, the next entry read “idem, 187–189,” meaning the same work.
In older legal notes, idem could signal that the same judge or statute was meant again.
Common combinations
- idem in a footnote
- Use idem in a footnote only when your citation style allows Latin abbreviations.
- idem citation
- The idem citation saved space but confused readers unfamiliar with the convention.
- idem versus ibid.
- The style sheet explained idem versus ibid. so students would not mix them.
Synonyms and how they differ
- ibid.
- Ibid. means the same place or source as the immediately preceding note, while idem points back to the same author or work more generally.
- op. cit.
- Op. cit. refers to a work cited earlier and usually follows an author’s name, not a bare repeated reference.
- ditto
- Ditto is informal and repeats wording or meaning in lists; it is not suitable for scholarly citations.
Commonly confused: idem or ibid.? idem or et al.?
idem vs ibid.
Ibid. repeats the exact preceding source, often with a new page number; idem repeats the author or work identity, so context and style guide matter.
idem vs et al.
Et al. shortens a list of multiple authors, while idem refers back to a single already-named author or source.
Practice
In a footnote where the previous note gave a full reference, and the new note concerns a different book by that same author, which marker best fits a style that accepts Latin citation terms?
Choose one answer.
Idem signals the same author or work just mentioned without rewriting the name; ibid. would mean the same exact source as the note above, which fails if the book differs, and op. cit. needs a named author in the note.
Make it your own
Write a sentence using “idem”, then check it and compare it with the examples above.