steroid

steroid /ˈstɛˌroɪd/ noun
plural steroids
steroid
/ˈstɛˌroɪd/
noun
plural steroids
Britannica Dictionary definition of STEROID
[count]
1 
: a natural substance that is produced in the body
2 
: anabolic steroid

on steroids

1 
: using anabolic steroids
2 
US, informal + humorous : very large or impressive