立ち所に

たちどころに【立ち所に】

〔すぐに〕 at once; immediately; directly; instantly; 〔即時に〕 in an instant [a moment, a twinkling]; in no time; 〔その場で〕 on the spot; outright; then and there; 〔即席に〕 extempore; offhand; impromptu; on the spur of the moment.

●その薬を飲んだらたちどころに痛みが消えた. When I took the medicine the pain went away at once [immediately, etc.].

・先生が一喝すると教室の騒ぎはたちどころにおさまった. One bellow from the teacher and immediately the noise in the classroom subsided.

・彼はたちどころに長篇詩を作った. He composed a long poem on the spot.