Equis

As you know, equis is the name of the letter x. However, as an adjective it conveys the idea of disappointingly ordinary or unimpressive. It's perfect for dismissing something — or someone — as unworthy of your attention.

• Un partido equis. This could refer to one of those small, inconsequential political parties that receives state funding but has no chance of being influential, much less of winning.
• Es equis. He's plain, ordinary, conventional, without redeeming qualities. Basically, someone who doesn't meet your standards.
• Una fiesta equis. A disappointing party with lame music, uninteresting people, no alcohol. To emphasize that the party was boring or tedious, you could say it was pesada or — more crudely — de hueva.

• You can modify equis with intensifiers: muy equis, bastante equis, súper equis
• Equis can modify a verb: Canta equis. He's not a great singer.
• The form is invariable: su fiesta equis, sus fiestas equis
• It comes in handy as a one-word response:
  — ¿Qué tal tu día?
  — Equis.
• In formal situations, choose a standard alternative: un partido equis → un partido sin importancia, un partido cualquiera

Un tache

The kind of x used for crossing something out would not be una equis but rather un tache, from the verb tachar, cross out. On a form, you can indicate your selection by writing un tache ✗ instead of una palomita ✓.

Una tacha

The feminine counterpart, una tacha, refers to a hit of the recreational drug ectasy, nicknamed X in English.