- cautionary, preventive, prophylactic - tending to ward off; "the swastika...a very ancient prophylactic symbol occurring among all peoples"- Victor Schultze
Antonym: unprotective (indirect, via protective)
- admonitory, cautionary, exemplary, monitory, warning - serving to warn; "shook a monitory finger at him"; "an exemplary jail sentence"
Antonym: persuasive (indirect, via dissuasive)