奥
オウ, おく, おく.まる, くま, お, おお, おん, つ, のく
heart, interior
JLPT2 G7 S12 F1018
The relevant seal inscription form is 共# (act jointly) + an element combining 釆 scattered seeds (→ fine objects) and 宀 roof/building → people searching for a small object in the *deep*, winding recesses of a structure (compare 究 and 探) → *recesses* (of a valley); *depths*; *secret*; *inner part*; *in one's heart* → *obscure*; *mysterious*; *profound*. Also, *corner*, *back room* and *wife* (← woman kept in seclusion).
[Full Kanji Etymology List]