Used in Spain, 'tronco de' is a colloquial phrase indicating surprise, disbelief or exasperation. It can be translated to 'what the hell' or 'what on earth'.
Examples
- Spanish: '¡Tronco de! ¿Cómo es posible que hayas terminado todo el trabajo en una hora?'
- English: 'What the hell! How is it possible that you have finished all the work in one hour?'