without lapse of time; without delay; instantly; at once

Please telephone him immediately.

with no object or space intervening.

closely

immediately in the vicinity.

without intervening medium or agent; concerning or affecting directly.

Chiefly British . the moment that; as soon as.

adverb

eventually , later , never , after a while , by and by , hereafter

adverb

anon , at short notice , away , directly , double-time , forthwith , hereupon , in a flash , in a jiffy , in a new york minute , in nothing flat , instantaneously , instanter , instantly , like now , now , now or never , on the dot , on the double * , on the spot , pdq , promptly , pronto * , rapidly , right now , shortly , soon , soon afterward , straight away , straight off , summarily , thereupon , this instant , this minute , tout de suite * , unhesitatingly , urgently , without delay , without hesitation , instant , right away , right off , straightaway , atonce , at the drop of a hat , instantaneous , straightway , tout de suite