If you knock a person or organization off their perch, you cause them to lose their important or leading position. Note: A perch is a pole, branch or other place where a bird sits to rest. For the regional firms this is an excellent time to knock London firms off their perch. Note: You can also say that a person or organization falls off their perch if they lose their important or leading position. There'll be no end of people ready to laugh when you fall off your perch. Note: You can use topple instead of fall. As one after another of the star companies of the 1980s fall on hard times, their high-flying executives are toppling from their perches.