Easton's Bible Dictionary (1897)
A poetical name for the people of Israel, used in token of affection, meaning, “the dear upright people” (Deut. 32:15; 33:5, 26; Isa. 44:2).
Smith's Bible Dictionary (1863)
” With the intensive termination Jeshurun would then denote Israel as supremely happy or prosperous, and to this signification the context in (32:15) points.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
JESH'URUN (dearly beloved), a symbolical name for Israel,Deut 32:15; Deut 33:5, Deut 33:26, and once, by mistake, Jesurun. Isa 44:2. The "he" in Deut 33:5 refers not to Moses, who is never called a king, but to the Lord, who was the Head of the theocracy.