|Easton's Bible Dictionary|
A remnant shall escape or return (i.e., to God), a symbolical name which the prophet Isaiah gave to his son (Isaiah 7:3), perhaps his eldest son.
Int. Standard Bible Encyclopedia
she-ar-ja'-shub or jash'-ub (she'ar yashubh, "a remnant shall return"; Septuagint ho kataleiphtheis Iasoub): The son of Isaiah, who accompanied him when he set out to meet Ahaz (Isaiah 7:3). The name like that of other children of prophets (compare "Immanuel," "Mahershalal-hash-baz," "Lo-ruhamah," etc.) is symbolic of a message which the prophet wishes to emphasize. Thus Isaiah uses the very words she'ar yashubh to express his oft-repeated statement that a remnant of Israel will return to Yahweh (Isaiah 10:21).
Shear-jashub (1 Occurrence)
Isaiah 7:3 Then said Jehovah unto Isaiah, Go forth now to meet Ahaz, thou, and Shear-jashub thy son, at the end of the conduit of the upper pool, in the highway of the fuller's field; (See JPS ASV BBE DBY WBS YLT NAS)