adverb
Etymology: steep (I) + -ly
1. : at a sharp angle : abruptly , precipitously , sharply
the train swept steeply down toward … the Swiss border — Joseph Wechsberg
the ground at once shelves steeply toward the north — James Whyle
a steeply sloping roof
2. : at a rapid rate : swiftly
gasoline consumption rose steeply when rationing was ended — Lamp
the steeply declining trend of the population — Alzada Comstock
dropped steeply into unconsciousness — Irwin Shaw