Not used as an ordinary word - it is an old graphic variant of 和 kept alive almost solely in personal names, most famously the Qing statesman 翁同龢. Modern Chinese always writes 和.
register
Archaic and onomastic only; you see it in historical names and etymology notes, never in current writing.
The left side is 龠, a multi-reed panpipe. Tones blending sweetly from such a pipe give the original idea of harmony - the meaning later inherited by 和.
