词根：-cad-, -cid-, -cas-

【词根含义】：落下,降临,发生

【词根来源】：来源于拉丁语动词cado, cadere, cecidi, casus(落下), 落下意味着降临, 降临意味着意外发生。

【同源单词】：decadence, decay, accident, accidental, accidentally

前缀：oc-, op-, of-

【词根含义】：相反;离开;对面;来,临近;加强意义

【词根来源】：ob-的变体, oc-用在c前; of-用在f前; op-用在p前。

【同源单词】：occasion, occasional, occupant, occupation, occupy

词根词缀：cad-, cas-, cid-

【来源及含义】Latin: to fall, befall

【相关词根词缀】 A cross reference of other word family units that are related directly, or indirectly, to: "chance, luck, fate": aleato-; auspic-; fortu-; -mancy; serendipity; sorc-; temer-; tycho-.

【同源单词】accidence, accident, accidental, accidentally, accidently, cadaver

词根词缀：ob-4

【来源及含义】Latin: down

【相关描述】Before c, ob- becomes oc-; before f, ob- becomes of-; before g, ob- becomes og-; before p, ob- becomes op-; before m, ob- becomes o-

【同源单词】occasion