Possible Clues:

• Measurement from side to side
• Wide measurement of diameter in pants, perhaps
• Use your loaf to start to being a wide boy
• Broadly speaking, that's more than half baked
• Use your loaf to start to get abroad, perhaps
• Use your loaf to start to find how wide the is
• Liberality with cash before Thursday
• It's a bit thick to have to draw about five hundred of this
• To make it wide put five hundred more into 21 across
• Measure devised by the Bard