apo-

1.
a prefix occurring originally in loanwords from Greek, where it was joined to verbs, deverbal forms, and other parts of speech. Among its functions in Greek, apo-, has the spatial sense “away, off, apart” (apogee; apocope; apostasy; apostrophe); it occurs with deverbals that denote a response or defense (apodosis; apology) and is found on verbs having perfective force relative to a corresponding simple verb (apoplexy; aposiopesis). In modern scientific coinages in English and other languages, apo-, marks things that are detached, separate, or derivative (apocarpous; apoenzyme).
Also, especially before a vowel, ap-.
Origin
< Greek, prefixal use of apó; akin to off, Sanskrit apa, Latin ab
British Dictionary definitions for apo-

apo-

prefix
1.
away from; off: apogee
2.
indicating separation of: apocarpous
3.
indicating a lack or absence of: apogamy
4.
indicating derivation from or relationship to: apomorphine
Word Origin
from Greek apo away, off
Word Origin and History for apo-

before vowels ap-, word-forming element meaning "from, away from, separate, free from," from Greek apo "from, away from; after; in descent from," in compounds, "from, asunder, away, off; finishing, completing; ceasing from; back again," from PIE root *apo- "off, away" (cf. Sanskrit apa "away from," Avestan apa "away from," Latin ab "away from, from," Gothic af, Old English of "away from").

apo- in Medicine

apo- or ap-
pref.

  1. Away from; off: aponeurosis.

  2. Separate: apocrine.

  3. Without; lacking; not: apoferritin.

  4. Related to; derived from: apomorphine.