hypergolic
adjective
hy·per·gol·ic ˌhī-pər-ˈgä-lik 
1
: igniting upon contact of components without external aid (such as a spark)
2
: of, relating to, or using hypergolic fuel
hypergolically
ˌhī-pər-ˈgä-li-k(ə-)lē
adverb 
Example Sentences
Recent Examples on the Web Lasting about 2 minutes and 40 seconds, the video shows instances where Pythom employees appear to be handling the Eiger rocket and its hypergolic propellants with less than industry-standard care. 
Eric Berger, Ars Technica, 15 Apr. 2022 Jiuquan currently only handles launches of older hypergolic Long March rockets and solid rockets, necessitating a new complex. Eric Berger, Ars Technica, 21 Jan. 2022 Unlike its predecessor, the Titan II used hypergolic propellant, with fuel and oxidizer stored in the missile—at room temperature—and mixed to launch almost instantaneously. Vince Guerrieri, Popular Mechanics, 18 Sep. 2020
Eric Berger, Ars Technica, 15 Apr. 2022 Jiuquan currently only handles launches of older hypergolic Long March rockets and solid rockets, necessitating a new complex. Eric Berger, Ars Technica, 21 Jan. 2022 Unlike its predecessor, the Titan II used hypergolic propellant, with fuel and oxidizer stored in the missile—at room temperature—and mixed to launch almost instantaneously. Vince Guerrieri, Popular Mechanics, 18 Sep. 2020 Word History
Etymology
German Hypergol a hypergolic fuel, probably from hyper- + erg- + -ol (hydrocarbon)
First Known Use
1947, in the meaning defined at sense 1
- line of force
- line of fortune
- line of Head
- line of Health
- line of Heart
- line of induction
- line of influence
- line of Intuition
- line of least resistance
- line of Life
- line of Liver
- line of march
- line of Marriage
- line of Mars
- line of Mercury
- line of metal
- line of nodes
- line of position
- line of pressure
- line of Protection
- line of reasoning
- line of resistance
- line of Saturn
- line of scrimmage
- line of sight