The compound word 坦率 (tǎnshuài) is formed through the combination of two independent semantic components, where each character contributes meaning to create a nuanced abstract concept. The first character, 坦, originally means "flat" or "level", extending metaphorically to "open" or "without concealment". The second character, 率, carries meanings of "straightforward", "to lead", or "without guile". When combined, their meanings fuse into the idea of "flat-out straightforwardness", forming a disyllabic word that conveys the quality of being frank, candid, or direct in speech and manner. This exemplifies a common Chinese word-formation method where two synonyms or near-synonyms are paired to reinforce and specify a shared abstract trait.