Related Clues:

• Unable to have offspring
• Mulish
• Lab so clean, unable to reproduce results
• Unable to reproduce
• Ineffective steps taken to protect top female
• Wilful son destined to conceal objection from East
• Bob turns out to be refractory
• Bacteria-free
• Unproductive way European money once got raised
• Rest and lie about, being unproductive
• The way to cause annoyance, staying obstinate to the end like a mule
• Clean crackers set cheese off
• Pig-headed objections raised and almost carried
• Unable to have children
• Uninspired setter to get angry