He was born Itsye Mordkhe Schaechter in the then-Romanian town of Tshernovits (in Yiddish; known in German as Czernowitz, in Romanian as Cernăuţi, and in Ukrainian as Chernivtsi).

[2] Schaechter became fascinated with Yiddish as a student, and he decided to study linguistics at the University of Bucharest.

Following his death, his daughter Gitl Schaechter-Viswanath and former student and colleague Paul Glasser published the Comprehensive English Yiddish Dictionary based on his lexical research.

His mother, Lifshe Schaechter-Widman, wrote a memoir, Durkhgelebt a Velt (A Full Life) in 1973, and served as a resource for folksong researchers with her recording Az Di Furst Avek (When You Go Away).

His sister, Beyle Schaechter-Gottesman, a Yiddish poet and songwriter, published books together with Charne Schaechter, her sister-in-law.

His nephew, Itzik Gottesman, is an contributor to The Forward and the online journal In Geveb, and a scholar of Yiddish folklore.