Possible Clues:

• Longest side of a right-angled triangle
• Element of the Pythagorean theorem
• The long side of a right-angled triangle
• Longest side of a right triangle
• Needle with point around figure's side
• Longest of three years in penthouse, debauched
• Long side of right-angled triangle
• Needle shared by a few forming long line?
• A needle for drugs shared by a number in the side
• Longest side of right-angled triangle