i know Allah Ghaleb means something like Allah is the strongest/mightiest/most victorious but when exactly is this expression used?
and also, what does motamarred mean? is it related to being sick (mareed) ?
chukran 
No , mutamarrid is not from mareed, because mareed is with “Dad”, mutamarrid is with “dal” & it means “a rebel”.
Allah ghaleb, means that his will overcomes our plans & views, & it’s mostly said when sth happen that we couldn’t stop.
ok thanks!!! i see the difference now