Synonyms for Instantly (same or very similar meaning)
WordNet sense 1 (without delay or hesitation; with no time intervening):
directly, forthwith, immediately, now, straightaway, at once, in real time, like a shot, straight off, right awayWordNet sense 2 (without any delay):
instantaneously, outright, in a flashFrom the ODE community, based on WordNetadd/edit