Possible Clues:

• Measure once shortened, divided by two
• Copper section, in length between foot and yard
• Copper coin couple found in yard, perhaps, long ago
• Ark measurement
• Ancient linear measure
• Biblical measure of length
• Piece of copper the length of one's arm
• Measurement for 22-Down
• Measurement whose name derives from the Latin for 'elbow'
• Youngster with oomph? 25 many years ago!