/ˈtrefo/
OriginBorrowed from German Treff, Russian тре́фы (tréfy), Polish trefl and French trèfle, all from Latin trifolium. Equivalent to tri (“three”) + folio (“leaf”).
- The suit of clubs, marked with the symbol ♣.
Formstrefon(accusative, singular) · trefoj(plural) · trefojn(accusative, plural)
Source: Wiktionary