ソウ  
おも.う 
() think () thought
                 
そう (n) (1) conception, idea, thought, (2) (Buddh) samjna (perception)
そうぞう (n,vs,adj-no) imagination, guess
そうてい (n,vs) hypothesis, supposition, assumption

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Etymologies: 中文字譜 : 説文解字