Answer:
No Yiddish is a Germanic language. (Middle - High German). Actually Yiddish is an older language than Modern German. Yiddish does use a Semitic alphabet (Hebrew). At least 20% of Yiddish words are of Semitic origin. Mostly Hebrew. A little Aramaic. Yiddish also has French and Italian influences. Many Slavic words are in Yiddish also. Since Jews started to move to the US many English words also became part of the Yiddish language.
Mien Plomenik svim in der Yam = My nephew swims in the sea. Mien = my German, Plomenik nephew Slavic, svim swim German, in = in German, der = the German, Yam = Sea Hebrew