佚書[issho] lost book
佚する[issuru] to lose (a chance)
佚楽[itsuraku] pleasure
安佚[anitsu] (idle) ease

放佚[houitsu] self-indulgence
散佚[sanitsu] being scattered and ultimately lost
淫佚[initsu] debauchery

威張り散らす[ibarichirasu] to domineer
胃散[isan] stomach medicine
逸散に[issanni] at top speed
一目散[ichimokusan] at full speed
一目散に[ichimokusanni] at full speed

雲散霧消[unsanmushou] vanishing like mist
解散[kaisan] breakup
拡散[kakusan] scattering
閑散[kansan] deserted (esp. store, market, town, streets)
言散らす[iichirasu] to spread (a report)