ˈbʊk.lət bɹoʊˈʃʊɚ ˈbɹəʊ.ʃə(ɹ) kʌsp ˈfoʊɫdɚ ˈfəʊldə ˈliːflɪt ˈpæmf.lɪt a thin triangular flap of a heart valve a small book usually having a paper cover part of a compound leaf