Standard Lemma guide

insidiousness

noun · 3 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

No pronunciation record was provided for this word.

1

noun

Meaning 1

A surreptitious harmfulness, quality of entrapment, or treacherousness; the characteristic of being insidious.

Definition source: English Wiktionary via Wiktextract

Usage: uncountable, usually

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

the quality of being designed to entrap

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: perfidy, perfidiousness, treachery

3

noun

Meaning 3

subtle and cumulative harmfulness (especially of a disease)

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: harmfulness, injuriousness

History

Etymology

Etymology tree English insidious Proto-Germanic *-inōną Proto-Indo-European *-dyé- Proto-Germanic *-atjaną Proto-Indo-European *-tus Proto-Germanic *-þuz Proto-Germanic *-assuz Proto-Germanic *-inassuz Proto-West Germanic *-nassī Old English -nes Middle English -nesse English -ness English insidiousness From insidious + -ness.

Across languages

Translations

2 source translations are retained for this English entry.

  • Bulgarian: коварство (kovarstvo) — the characteristic of being insidious
  • Spanish: insidia — the characteristic of being insidious