How to Pronounce “insidious”

American (US)

/ɪnˈsɪdi.əs/

British (UK)

/ɪnˈsɪdi.əs/

adjective — Causing harm in a stealthy, often gradual, manner.

Where the stress falls. “insidious” has 4 syllables, and the transcription /ɪnˈsɪdi.əs/ puts the primary stress mark (ˈ) before the second one — so the second syllable is the longest and loudest. The others are said quickly and lightly.

An unstressed vowel reduces to schwa. /ɪnˈsɪdi.əs/ contains a schwa /ə/ — the short, neutral “uh” that English unstressed syllables collapse into. Saying /ə/ there, instead of the vowel the spelling suggests, is most of what makes the word sound native.

What does "insidious" mean?

insidious (adjective): Causing harm in a stealthy, often gradual, manner.

How do you pronounce "insidious" in American vs British English?

Both accents use the same sequence of phonemes for "insidious", /ɪnˈsɪdi.əs/, so the difference you hear is in how the vowels are coloured rather than in which sounds are used. Play both on this page to compare.

What is the IPA transcription of "insidious"?

/ɪnˈsɪdi.əs/ in American English, /ɪnˈsɪdi.əs/ in British English.

Which syllable is stressed in "insidious"?

“insidious” has 4 syllables, and the transcription /ɪnˈsɪdi.əs/ puts the primary stress mark (ˈ) before the second one — so the second syllable is the longest and loudest. The others are said quickly and lightly.