precipitantly
/prɪˈsɪpɪt(ə)ntli/adverb
1With a rapid fall or descent; headlong; steeply, precipitously. Now chiefly figurative.
2With excessive hurry, without deliberation; hastily, rashly.
3With rapid movement, at great speed; suddenly, abruptly.
Origin
Mid 17th century; earliest use found in Jeremiah Dyke (bap. 1584, d. 1639), Church of England clergyman. Apparently from precipitant + -ly.