词根词缀：ex-, e-, ef-

【来源及含义】Latin: a prefix occurring in words of Latin origin used in the senses: out, out of, from; upward; completely, entirely; to remove from, deprive of; without; former [said of previous holders of office or dignity]

【相关描述】Before f, ex- becomes ef-; before all voiced consonants (as b, d, g, etc.) ex- becomes e-.

【同源单词】e pluribus unum, educate, educe, efface, effacement, effete