Possible Clues:

• An engagement in which English Queen appears up to the job?
• For Bill to correspond is good enough
• A river without measure of liquid - not river up to the job?
• Less than stellar
• It's enough to make Bill correspond
• Sufficient now to regard as similar
• Given enough notice to regard as an equal
• As temperature in a river it's just about sufficient
• Satisfactory, enough,
• Satisfactory, enough