遺失[ishitsu] loss
遺失物[ishitsubutsu] lost article
一失[isshitsu] disadvantage (defect, error)
一得一失[ittokuisshitsu] gaining some and losing some
栄養失調[eiyoushicchou] malnutrition

過失[kashitsu] error
見失う[miushinau] to lose sight of
失う[ushinau] to lose
失する[shissuru] to lose
失せる[useru] to disappear

一席[isseki] sitting
運転席[untenseki] driver's seat (in a car)
宴席[enseki] banquet
会席[kaiseki] meeting place
会席膳[kaisekizen] elaborate dinner tray

会席料理[kaisekiryouri] set of dishes served on an individual tray for entertaining guests
外野席[gaiyaseki] outfield bleachers
滑席[kasseki] sliding seat
寄せ席[yoseseki] musical hall
議席[giseki] parliamentary seat

異議[igi] objection
異議なく[iginaku] without demur
井戸端会議[idobatakaigi] content-free chat
一議[ichigi] word (opinion, objection)
円卓会議[entakukaigi] round-table conference

横議[ougi] arguing persistently
下院議[kaingi] lower house (of Parliament, etc.)
下院議員[kaingiin] member of the lower house
下院議長[kaingichou] Speaker of the House (US, etc.)
下協議[shitakyougi] preliminary conference