Related Clues:

• Persistent in holding on
• (Of illness) slow developing over a long time
• Deep-seated — long-lasting
• Inexorable
• Not acute
• Enduring — constant
• With a lasting quality
• Hard-working without rubber on bikes it's said
• Single-minded dear, say, hides horse for Penny
• Determined to get female eating horse, then surprised ultimately
• Long-lasting, pain perhaps
• Enduring memory of sailor I had found at home at midnight
• Pursued in a persistent way
• Trendy — right-on at heart — yet enduring
• Clingy