unfoolish

adjective

1. resulting from or showing a lack of sense; ill-considered; unwise: a foolish action, a foolish speech.
2. lacking forethought or caution.
3. trifling, insignificant, or paltry.

adjective

1. unwise; silly
2. resulting from folly or stupidity
3. ridiculous or absurd; not worthy of consideration
4. weak-minded; simple
5. an archaic word for insignificant

adj.early 14c., from fool (n.) + -ish. Related: Foolishly; foolishness. Old English words for this were dysig, stunt, dol. see penny wise and pound foolish.