Related Clues:

• Spongy tissue like that lining an orange skin
• Inside skin of, say, orange
• White inner skin of an orange
• Inner skin of citrus fruit
• It is inside, soft inside
• Bare bones
• Most important part
• The white part of the orange
• White tissue in oranges
• Orange's white?
• Lining of rind - important part
• Fibrous part of fruit — essence
• Person or thing vital to an enterprise or organization
• Core — essence
• Heart of the matter provides horsepower to drive back over it