"Ishu" does not mean anything in Hebrew.
Perhaps you are looking of "Esav" (עשו) which shares all of the Hebrew letters in common with how "Ishu" would likely be spelled and means "Esau", Isaac's firstborn son. You may also be looking for Yeshu (ישו) or Yeshua (ישוע) both of which mean "Jesus".
the man = ha ish (האיש)
Ish Sheleg (איש שלג)
You can say both "Gever" - גבר or "Ish" - איש.
Ish Elokim (Deuteronomy 33:1).man of God = ish shel hashem (איש של ה׳)ish elohim (איש אלוקים)
Crazy Old Man in Hebrew is "Ish Zaken Meshuga" - איש זקן משוגע.
There is no Hebrew word for zealot. Modern Hebrew uses the word fanát (×¤× ×˜) which comes from the English word "fanatic."
man - Ish (איש) men - Anasheem (אנשים)
atah ish yafeh (אתה איש יפה)
atah ish fantasti (אתה איש ×¤× ×˜×¡×˜×™)
Brit could come from the Hebrew word meaning "covenant" This could make sense as Ish is the Hebrew word for "man"
There is no such translation in Hebrew, but there are many theories. The most popular is that it's a corruption of the Hebrew phrase Ish Krayyot (איש קריות), which means "man of Krayyot (a town)".
"You will be a great man" = Teheyeh ish gadol. (תהיה איש גדול)