I'm guessing that you don't really want the Yiddish definition. You want the
definition, in English, of the words "Boruch dayan ...", which you presume to be
Yiddish words.
The words are Hebrew, and mean "Bless the judge" ... a fairly meaningless and
not very useful fragment, mainly because it's an incomplete piece of a much
more common Hebrew phrase: "Baruch dayan emet.". That means "Bless the
true judge.". It's the appropriate first response when a Jew receives the news
that a friend, relative, or acquaintance has died; it's a blessing of the One who
ultimately gives life and takes life, and judges when each one shall begin and
end.
Welcome in Yiddish is "ברוך הבא" (pronounced "Brookh haboh").
Marianne Boruch was born in 1950.
Boruch Greenfeld was born in 1872.
Boruch Greenfeld died in 1956.
Boruch of Medzhybizh was born in 1753.
Boruch Ber Leibowitz was born in 1870.
Boruch Ber Leibowitz died in 1940.
Boruch Israel Dyner died in 1979.
Boruch Israel Dyner was born in 1903.
Boruch of Medzhybizh died on 1811-12-04.
Eliyahu Boruch Finkel was born on 1947-12-25.
Eliyahu Boruch Finkel died on 2008-03-31.