1. adjective /ɡɹeɪt/
A great storm is approaching our shores.
b) Very good.
Dinner was great.
2. interjection /ɡɹeɪt/
a) Expression of gladness and content about something.
Great! Thanks for the wonderful work.
b) sarcastic inversion thereof.
Oh, great! I just dumped all 500 sheets of the manuscript all over and now I have to put them back in order.
3. noun /ɡɹeɪt/
Newton and Einstein are two of the greats of the history of science.
Wikipedia foundation.