Fleshy fruit - citrus: thick pulped, edible fruit, generally green, yellow or orange (mix of red and yellow).
Orange: fruit of the orange tree.
Segment: piece contained by two walls.
Wall: membrane that separates the segments.
Mesocarp or pulp: edible part of the fruit.
Pericarp or rind: inedible part of the fruit that covers and protects it.
Zest: rind of an orange.