To combine, to join up, to join together, to dovetail together.

Buddhist priest / monk

pair; double

chirping of birds

pouch / hold / content / insufficient / put in mouth

Big, robust

twins

foe, enemy, rival / resentment, enmity, grudge / harm, injury

Song (Chinese dynasty)

name of the state during the Zhou dynasty / the 劉宋 (Ryūsō), around 420-479 / the 北宋 (Hokusō, “Northern Song”) and 南宋 (Nansō, “Southern Song”) dynasties, spanning around 960-1279 / a surname