oxy-1

1.
a combining form meaning “sharp,” “acute,” “keen,” “pointed,” “acid,” used in the formation of compound words:
oxycephalic; oxygen; oxymoron.
Origin
< Greek, combining form of oxýs sharp, keen, acid

oxy-2

1.
a combining form representing oxygen, in compound words, sometimes as an equivalent of hydroxy-: oxychloride.
British Dictionary definitions for oxy-

oxy-1

combining form
1.
denoting something sharp; acute: oxytone
Word Origin
from Greek, from oxus

oxy-2

combining form
1.
containing or using oxygen: oxyacetylene
2.
a former equivalent of hydroxy-
Word Origin and History for oxy-

word-forming element meaning "sharp, pointed; acid," from Greek oxy-, comb. form of oxys "sharp, pungent" (see acrid). Also used as a comb. form of oxygen.

oxy- in Medicine

oxy- or ox-
pref.
Oxygen, especially additional oxygen: oxygenation.