Vertical
Perpendicular, Upright
な adjective, の adjective, noun
Something dangles straight down, making it perfectly vertical. If we wanted to get fancy, we could even say it's perpendicular to the floor.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
ロケットは垂直に発射した。
The rocket took off vertically.