A tour de force (See here under tour3, sense II.A.1.) is an impressive feat. The word (there are three tour, of differing etymologies) is ultimately from an Old French turn, a noun derived from what became tourner which through an elaborate series of semantic expansions acquired the meaning of "feat, demonstration, (magical/acrobatic) trick". One says similarly tour de magie/cartes ("magic/card trick") or avoir plus d'un tour dans son sac ("have more than a trick up your sleeve").
Originally it meant more literally "feat of strength or skill", but its meaning rapidly widened to the current more general one.
As far as I know, the phrase is relatively common in English as far as borrowed French phrases go.