拡散[kakusan] scattering
拡充[kakujuu] expansion
拡大[kakudai] magnification
拡大率[kakudairitsu] rate of magnification
拡張[kakuchou] expansion

拡張化[kakuchouka] enlargement
拡張可能[kakuchoukanou] extensible
拡張倍精度[kakuchoubaiseido] extended double-precision
繰拡げる[kurihirogeru] to unfold
軍拡[gunkaku] military expansion

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)