ex-
- : it becomes ef- before f; e- before b, d, g, j, l, m, n, r, or v; often ec- before c or s; and, in many words of French origin, es-
- forth, from, out: extubate
- beyond: exurb
- away from, out of: explant
- thoroughly
- upward
- without, not having: exsanguine
- former, previous, previously: used in hyphenated compounds: ex-president, ex-convict, ex-wife
exo-: used before a vowel
See ex- in American Heritage Dictionary 4
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