窓
ソウ, ス, まど, てんまど, けむだし
window, pane
JLPT3 G6 S11 F1186
The variant form 窗 is the original form: 穴 hole + 囱# a compressed stream of smoke escaping a ventilation hole (compare 向) → *window*. 窓 is a variant form of 窻, which is 穴 hole + 悤, an obsolete character indicating agitation (likened to the heart being compressed).
[Full Kanji Etymology List]