aburrirse VERB to get bored
If you want to say that you’re bored in Spanish, use the expression estar aburrido, to be bored. But to say ‘get bored’ you need to use the verb aburrir (to bore) and put se on the end to make it reflexive.
Me aburro viendo la tele. I get bored watching television.
If you get really bored, you can use the phrase aburrirse como una ostra, which means to be bored stiff (word for word, to get as bored as an oyster).
There are quite a few verbs like this in Spanish. Some other examples are enojarse and enfadarse (which both translate as to get angry), cansarse (to get tired) and enfriarse (to get cold).