GNU Collaborative International Dictionary of English

Found 2 definitions

1.       
   In- . [See In, prep. Cf. Em-, En-.] A prefix from Eng. prep. in, also from Lat. prep. in, meaning in, into, on, among; as, inbred, inborn, inroad; incline, inject, intrude. In words from the Latin, in- regularly becomes il- before l, ir- before r, and im- before a labial; as, illusion, irruption, imblue, immigrate, impart. In- is sometimes used with an simple intensive force.
   1913 Webster
         
       

2.       
   In- . [L. in-; akin to E. un-. See Un-.] An inseparable prefix, or particle, meaning not, non-, un- as, inactive, incapable, inapt. In- regularly becomes il- before l, ir- before r, and im- before a labial.
   1913 Webster