The word 千辛万苦 is formed by combining the numeral 千 (thousand) with 辛 (hardship) and the numeral 万 (ten thousand) with 苦 (suffering), creating the parallel compounds 千辛 and 万苦; these are then joined into a single idiom where the numerals serve to exaggerate the intensity and multitude of the adversities, resulting in a meaning that conveys extreme toil and distress.