In Spanish slang, 'violinista' refers to a person who is always on the sidelines, or someone who is always waiting or left behind. It can also refer to a third person who is feeling left out while his/her two friends are in a romantic relationship.
Examples
- Spanish: Siempre salgo con Juan y su novia, me siento el violinista.
- English: I always go out with Juan and his girlfriend, I feel like the third wheel.