Other forms: interfering, interfered, interferes
To interfere is to push into something that is not yours to decide, and get in its way. The neighbour who rearranges your bins, the manager who redoes work the team already finished, the country accused of interfering in someone else's election.
Two prepositions do two different jobs: you interfere IN a matter or an argument, and you interfere WITH a thing or a process, as when the roadworks interfered with the phone signal. The noun is interference, which is also the crackle on a radio when another signal cuts across, and in physics what two waves do when they meet. Interfering is a complaint, never a compliment: nobody calls their own advice interfering. One warning worth having, since British news reports use interfere with a person as a guarded way of saying sexual assault: say interfere in when you mean meddling.
1verbinterfereTo involve yourself in something that is not your concern and get in its way.
“His mother interferes in every decision they make.”
synonyms: meddle, intrude
2verbdisturbTo disturb or obstruct a process, signal or activity.
“The building work interfered with the phone signal all week.”
Too few real examples of this word to estimate which sense is commonest.
Also accepted in games: meddle
Interfere comes from Old French entreferir, made of entre-, between, and ferir, to hit or to strike, which goes back to Latin ferio. So the word began as a blow landing in between, and that is exactly what interfering still is: a hand shoved into the middle of something already under way.
Old French
entreferir
English, today
interfere
Built from
From Old French entreferir, from entre- + ferir (“to hit, to strike”), itself from the Latin - verb ferio.
Etymology from Wiktionary, CC BY-SA