| Word | Definitions | Synonyms |
|---|---|---|
| foolhardy | (adjective) marked by defiant disregard for danger or consequences | Synonyms: heady, rash, reckless |
| fooling | (adjective) characterized by a feeling of irresponsibility | Synonyms: casual |
| foolish | (adjective) devoid of good sense or judgment | - |
| (adjective) having or revealing stupidity | Synonyms: anserine, dopey, dopy, gooselike, goosey, goosy, jerky | |
| foolproof | (adjective) not liable to failure | Synonyms: unfailing |