il-1

1.
variant of in-2. (by assimilation) before l: illation.

il-2

1.
variant of in-3. (by assimilation) before l: illogical.
British Dictionary definitions for il-

il-

prefix
1.
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 il-

assimilated form of Latin prefix in- used with words beginning in l-; see in-.

il- in Medicine

il- 1
pref.
Variant of in-1.

il- 2
pref.
Variant of in-2.