big no-no
- tabooCultural or social prohibition
- forbiddenNot allowed
- off-limitsProhibited from access
- unacceptableNot meeting required standards
- violationBreaking of rules
faux pas · mistake · blunder · sin · transgression · rule-breaking · dealbreaker · unforgivable · crossing the line · red flag · warning · shame · scandal · outrage · disgrace · etiquette · social death · career suicide
social/behavioral acceptability
big no-nobest practice
Accepted superior method
green light · golden rule · standard practice · done thing · proper etiquette
advisability/prudence
big no-nogood idea
no-brainer · safe bet · winning strategy · best bet · way to go
acceptability/permissibility
big no-noA-OK
Completely satisfactory
green light · go-ahead · fair game · kosher · permissible