嘆
タン, なげ.く, なげ.かわしい
sigh, lament, moan, grieve
JLPT1 G7 S13 F1584
口
mouth + ?# as described in
漢
for the sound alone to simulate a sigh (compare
歎
) → *grieve*; *lament* → *mourn*; *deplore*; *regret*.
[Full Kanji Etymology List]