From a Slavic language, likely Upper Sorbian pjata given the unstressed ending; compare Ukrainian п'ята́ (pʺjatá) and Russian пята́ (pjatá). пя́тка (pjátka) is unlikely given the missing K, which would have yielded פּיאַטקע (pyatke).
פּיאַטע • (pyate) f, plural פּיאַטעס (pyates)