annotation

annotation — noun

1. a brief comment, explanation, or reference written next to or attached to part o

1.nounC1
Definition

a brief comment, explanation, or reference written next to or attached to part of a book, document, diagram, or image, usually meant to help readers understand a difficult passage or to record what someone thinks about it.

Example

Professor Liu's annotations in the margins explained every Latin phrase for her students.

annotations in the margins (typical location)

The old Bible was full of handwritten annotations from three generations of the Cohen family.

handwritten annotations from + source

Common collocations
  • scholarly annotation
  • marginal annotation
  • handwritten annotation
  • annotations in the margins
  • with annotations
Synonyms
  • note

    much broader and less formal; an annotation is specifically tied to another text

  • comment

    any spoken or written remark; an annotation is always written and attached to source material

  • gloss

    scholarly synonym, especially for explaining a single word in an old or foreign-language text

  • footnote

    specifically printed at the bottom of the page; annotation can sit anywhere

Grammar Patterns

annotation on/to + noun

annotations in + text

Usage Note

Most often plural ('annotations'). The container is named with 'in' (in the margins, in the text) but the topic is named with 'on' (annotations on the poem). Distinguish from sense 2: this sense is the visible note itself; sense 2 is the activity of producing such notes.

Common Mistakes

I made an annotation about the chapter on page 12.
I made an annotation on page 12 about the chapter.
use 'on/in' for where the note sits, 'about' for what it discusses.
The book has many annotation.
The book has many annotations.
countable; use the plural with 'many'.

2. the activity or process of adding short explanations, labels, or tags to a text,

2.nounC1
Definition

the activity or process of adding short explanations, labels, or tags to a text, image, or set of data — for instance, marking each word in a sentence with its grammatical role, or labeling objects in a photograph for a computer to learn from.

Example

Manual annotation of the medical scans took the research team almost six months.

uncountable: annotation of + noun

The company hires linguists for the annotation of training data used in language models.

annotation of training data (data-science use)

Common collocations
  • manual annotation
  • image annotation
  • data annotation
  • annotation tools
  • annotation guidelines
Synonyms
  • labelling

    common in machine-learning contexts; emphasizes attaching a category to each item

  • tagging

    lighter and more digital; suggests short keywords rather than full explanations

  • commentary

    fuller and more literary; the result is connected prose rather than separate notes

Grammar Patterns

annotation of + noun

annotation tools/software

Usage Note

Uncountable in this sense — say 'annotation is slow', not 'an annotation is slow'. Frequently appears as a compound modifier ('annotation tool', 'annotation task', 'annotation guidelines'). Distinguish from sense 1: if you can replace the word with 'note', use sense 1; if you can replace it with 'labelling' or 'tagging', use sense 2.

Common Mistakes

The annotations of the dataset took a year.
The annotation of the dataset took a year.
when you mean the process, use the singular uncountable form.

Word family

Synonym discussion

Sense: noun/1

All five words name something written to help readers understand another text, but they differ in scope and placement. A 'note' is the broadest term and can stand alone — a sticky note on the fridge counts. An 'annotation' is always tied to a specific passage, image, or data point and usually adds explanation rather than personal reminder. A 'footnote' sits in a fixed location, the bottom of the page, and is typeset by the author or editor; an annotation can be handwritten in the margins by any reader. A 'gloss' is the most scholarly: traditionally it explains a single difficult word, often in older or foreign-language texts. 'Commentary' is the longest form — connected prose rather than scattered notes. Compare: 'Her marginal annotations on the poem' (handwritten beside the lines) versus 'the editor's footnotes' (printed below) versus 'a Latin gloss above each word' (single-word definitions).

annotation ↗note ↗footnoteglosscommentary ↗

Common collocations

Nouns

  • annotation tool
  • annotation software
  • annotation task
  • annotation guidelines
  • edition with annotations

Adverbs

  • heavily annotated
  • lightly annotated

Phrases

  • full of annotations
  • covered in annotations
  • scholarly annotations

Prepositions

  • annotation on
  • annotation in
  • annotation to
  • with annotations

Etymology

LatinLate LatinMiddle FrenchMiddle EnglishEnglish

From Late Latin 'annotatio', a noun built on the verb 'annotare' meaning 'to put a mark on' — formed from 'ad-' (toward, on) plus 'notare' (to note, mark down), itself from 'nota' (a written sign). The word entered English in the early 1400s through Middle French, first describing written remarks added beside legal or religious texts, and later expanding to any explanatory note or, in modern computing, the act of labelling data.