precipitously.

In a precipitous manner. Abruptly, perilously, sharply, steeply, severely

In the west of Ireland, the Cliffs of Moher drop precipitously into the North Atlantic.

In a precipitous manner. Abruptly; with no notice or ceremony: in a sudden or hasty manner, instantly, quickly.

Shortly after the conversation turned to the results of the recent election, John silently stood from the table, and without explanation, precipitously walked out on the dinner party.

In a precipitous manner. done with a lack of proper decorum, or without adequate thought, care or concern for consequenses.

In signing that contract without reading all of the provisions, I have performed what was a legal requirement most precipitously, leading me to wish that I had taken more care.

Look here son, in stealing that candy bar from Belsito's market, you have acted precipitously in the extreme; now you will have the unenviable responsibility of telling Mr. Belsito what you have done, and of expressing your heartfelt regret.