mark someone's card
Proposed by a contributor, not yet supported by evidence.
Meaning · English
to warn or inform someone of a potential problem
Nghĩa · Tiếng Việt
Cảnh báo hoặc thông báo cho ai đó về vấn đề tiềm ẩn
Machine-translated — suggest a fix
Literally: mark a playing card to cheat
Where it’s used:
Used
Widespread English
Examples
The teacher marked the student's card about the upcoming exam
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 “mark someone's card” mean?
to warn or inform someone of a potential problem Literally: mark a playing card to cheat
Is “mark someone's card” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.