This japanese word means: magnifique, excelent, fantastic and etc. This word is mostly used by one of the antagonists Goku Black from the anime Dragon Ball Super.
Zamasu: all of the ningen are dead.
Goku Black: *clapping* Subarashii!!!
Cell or Bio-Android Cell is one of the main antagonists of the famous anime Dragon Ball Z. He was created by Dr Gero. He is perfect, but Gohan still killed him.
"♪'P' is for 'priceless', the look upon your faces♪
♪'E' is for 'extinction', all your puny races♪
♪'R' for 'revolution', which will be televised♪
♪'F' is for how 'f**ked' you are, now allow me to repriiise♪
♪'E' is for 'eccentric', just listen to my song♪
♪'C' is for 'completion', that I waited for so long♪
♪'T' is for the 'terror', upon you I’ll bestow♪
♪My name is Perfect Cell, and I'd like to say...hello.♪"
— "The "Perfect" Guy"
This is used in TeamFourStar's series "Dragon Ball Z Abridged" after Cell attains his Perfect form.