From Wiktionary, the free dictionary
From Hebrew הִתְלַהֲבוּת.
התלהבֿות • (hislayves) n, plural התלהבֿותן (hislayvesn)
- enthusiasm, ardor
- Uriel Weinreich (1977) “ardor”, in Modern English-Yiddish, Yiddish-English Dictionary, New York: Schocken Books, page 18