el/la tonto / tonta (adjective, noun)

Frequency star
  1. silly, foolish, dumb
  2. fool, idiot (as a noun)

Me encanta que siempre se ría de mis chistes tontos.

I love that they always laugh at my stupid jokes.

Seríamos tontos si no aceptáramos.

We would be foolish if we didn't accept.

Las negociaciones se estancaron por culpa de un malentendido tonto.

The negotiations stalled because of a silly misunderstanding.