accelerative
[ ak-sel-uh-rey-tiv, -er-uh-tiv ]
/ ækˈsɛl əˌreɪ tɪv, -ər ə tɪv /
adjective
tending to accelerate; increasing the velocity of.
Also
ac·cel·er·a·to·ry
[ak-sel-er-uh-tawr-ee, -tohr-ee] /ækˈsɛl ər əˌtɔr i, -ˌtoʊr i/.
Origin of accelerative
First recorded in 1745–55;
accelerate +
-ive