This list is too good not to give prominence to, it came from  Pampel Muse:

 Thank you for this great list, it helps me a lot while reading!

And I say this even though I'm German and many of the Yiddish terms in the book are also known in German language and are common until today, many of them with a different spelling though:

Forshpiel - german "Vorspiel" means foreplay or prelude
Freylekhs - close german term is "frohlocken" (to exult or rejoice)
Kibitzer - german "Kibitz" for lapwing
Luftmensch - literally "air person", means a person that lives from nothing, has no job
Macher - a maker, a man of action
Patzer - a mistake, a bumbler
Schlosser - locksmith or metalworker
Shtarker - "stark" in german means 'strong'
Shtekeleh - sounds similar to Switzerlandish "Stückele", sweet pastries
Shtetl - Städtl, Switzerlandish for a small city
Shtinkers - "Stinker" in german is said to someone who smells, also as pet name for babies + pets
Shvitz - "schwitzen" in german, to sweat or perspire
Tohubohu - in german "Tohuwabohu", chaos
Yahrzeit - "Jahreszeit" = season (summer, winter..)

There are many more, especially names of people, but also of places:

Untershtat - german "Unterstadt", similar to "downtown"
Platz - place or square
Shpilman - "Spielmann", overaged term for musician
Purimshpiel - "Spiel" in german means game or act
Nachtasyl - "night's asylum", name of a bar in the book
Krankheit - "illness", in the book a name of a weekend manager
Oysshtelung - "Ausstellung", exhibition
Adler street - "Adler" = eagle, street where Landsman grows up
Blat - name of a newspaper in the book, "Blatt" is a slang word for just this
Grill - BBQ