老天 literally means 'old heaven' and refers to Heaven or Providence in a Chinese folk-religious sense, often personified as a force that watches over people. You'll hear it in exclamations like 老天爷 (Heavenly Grandfather) or set phrases such as 老天有眼 (Heaven has eyes — justice is done). It carries a cultural weight similar to 'God' or 'Providence' in English, but without the monotheistic framework — think of it as a universal moral arbiter rooted in traditional Chinese cosmology.