im-1

1.
variant of in-2. before b, m, p: imbrute; immigrate; impassion.

im-2

1.
variant of in-3. before b, m, p: imbalance; immoral; imperishable.

im-3

1.
variant of in-1. before b, m, p: imbed; immure; impose.
British Dictionary definitions for im-

im-

prefix
1.
a variant of in-1 , in-2

in-1

prefix
1.
not; non-: incredible, insincere, illegal, imperfect, irregular Compare un-1
Word Origin
from Latin in-; related to ne-, nōn not

in-2

prefix
1.
in; into; towards; within; on: infiltrate, immigrate
2.
having an intensive or causative function: inflame, imperil
Word Origin
from in (prep, adv)
Word Origin and History for im-

variant of in- before -b-, -m-, -p-, in the sense of "not, opposite of" (immobile, impersonal) as well as "in, into" (implant, impoverish). See in-. In some English words it alternates with em- (1).

im- in Medicine

im- 1
pref.
Variant of in-1.

im- 2
pref.
Variant of in-2.