in·ter·fere / ˌintərˈfi(ə)r/ • v. [intr.] 1. (interfere with) prevent (a process or activity) from continuing or being carried out properly: a job would interfere with his studies. ∎ (of a thing) strike against (something) when working; get in the way of: the rotors are widely separated and do not interfere with one another. ∎ handle or adjust (something) without permission, esp. so as to cause damage: he admitted interfering with a van. ∎ Law attempt to bribe or intimidate (a witness).2. take part or intervene in an activity without invitation or necessity: she tried not to interfere in her children's lives | [as adj.] (interfering) interfering busybodies. 3. Physics (of light or other electromagnetic waveforms) mutually act upon each other and produce interference: light pulses interfere constructively in a fiber to emit a pulse. ∎ cause interference to a broadcast radio signal.4. (interfere with) Brit. sexually molest or assault (someone, esp. a child or young person) (used euphemistically).5. (of a horse) knock one foot against the fetlock of another leg.DERIVATIVES: in·ter·fer·er n.in·ter·fer·ing·ly adv.