(n)any of several Old World partially crustaceous or shrubby lecanoras that roll up and are blown about over African and Arabian deserts and used as food by people and animals
The Collaborative International Dictionary of English (GCIDE) v.0.53Collaborative International Dictionary (GCIDE)
n. Any of several Old World semicrustaceous or shrubby lecanoras that roll up and are blown about over African and Arabian deserts and used as food by people and animals; same as manna{ 2 }. [ WordNet 1.5 ]