что-нибудь

Pronoun

 * 1) (indefinite pronoun) anything, something (implies one does not care what, or does not have any particular thing in mind)

Usage notes
The particle -нибудь is used more often in spoken speech, while the particle -либо is used more often in writing. Apart from this, they are largely synonymous, with their use subject to stylistic and idiosyncratic preferences.