# polysemanticity

CEFR C2 · Noun

Source: https://englishreference.com/word/polysemanticity
Updated: 2026-09-28

## Definition

the property of a single artificial neuron firing in response to several completely unrelated concepts.

For teachers: the phenomenon whereby an individual neuron or activation dimension responds selectively to multiple distinct, semantically unrelated concepts or visual features.

## Examples

- A single neuron showed polysemanticity by activating for pictures of cats, guitars, and German text.
- The existence of polysemanticity makes it very difficult for humans to understand what individual neurons are calculating.
- Sparse autoencoders address polysemanticity by decomposing dense entangled activations into a much larger overcomplete dictionary of interpretable monosemantic directions.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.