Possible Clues:

• Unbreakable
• A woman keeping a note and cash, resisting all requests
• Immovable plug a worker discovered in pit
• A US woman eclipsing rival before end of election, very tough
• Unbreakable ’80s artist that is covering number
• The first person against the northeast being unyielding
• Hard type of man, worker in Eden originally
• Impervious to pleas, detain a man falsely
• Notice a chap with point that's very strong
• Giving an animated rendition is very hard