kaffir boom n 1: small semi-evergreen of South Africa having dense clusters of clear scarlet flowers and red seeds [syn: {Transvaal kafferboom}, {Erythrina lysistemon}] 2: small semi-evergreen broad-spreading tree of eastern South Africa with orange-scarlet flowers and small coral-red seeds; yields a light soft wood used for fence posts or shingles [syn: {Cape kafferboom}, {Erythrina caffra}]