swear by
Proposed by a contributor, not yet supported by evidence.
Meaning · English
to strongly believe in something's effectiveness or quality
Nghĩa · Tiếng Việt
tin tưởng mạnh mẽ vào hiệu quả hoặc chất lượng của điều gì
Machine-translated — suggest a fix
Literally: take an oath on
Where it’s used:
Used
Widespread English
Examples
She swears by this new diet.
AI-drafted example auto-approved by rule (illustrative, not a corpus attestation)
Sources & notes
Listed in Wiktionary’s “English idioms” category (retrieved 2026-07-29); definition pending editorial review. Definition drafted by AI (@cf/meta/llama-3.3-70b-instruct-fp8-fast) and auto-approved by rule on 2026-07-31; pending editor spot-check.
Common questions
What does “swear by” mean?
to strongly believe in something's effectiveness or quality Literally: take an oath on
Is “swear by” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.