不同
bùtóng · HSK 2
different
不 (not) + 同 (same) = not the same → different
不 negates and 同 means same/together, so 不同 literally reads as not-same. Compare 同 in 同学 (classmate, same-school) and 相同 (identical) to feel how negating it flips to different.
不 — single pictograph; bird flying upward
Originally a pictograph in oracle bone script, traditionally interpreted as a bird flying up toward the sky and unable to come down, suggesting negation or refusal. Over time it became the standard negation word in Chinese, used before verbs and adjectives to mean 'not'.
同 — 冂 enclosure + 一 + 口 mouth
Originally depicted multiple mouths gathered under one cover or enclosure, suggesting people speaking together in agreement. From this image of voices joining, it came to mean 'same,' 'together,' or 'alike.' The shared cover symbolizes unity.