up to something
Proposed by a contributor, not yet supported by evidence.
Meaning · English
involved in a secret or possibly dishonest activity
Nghĩa · Tiếng Việt
liên quan đến hoạt động bí mật hoặc có thể không trung thực
Machine-translated — suggest a fix
Literally: in a position to do something
Where it’s used:
Used
Widespread English
Examples
I think they're up to something, let's investigate
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 “up to something” mean?
involved in a secret or possibly dishonest activity Literally: in a position to do something
Is “up to something” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.