Related Clues:

• Nuts or crackers, take your pick
• Kind of duck
• Off one's trolley
• Like all primes but one
• Lacking a match
• Atypical
• Quite unusual
• Unmatched, as socks
• Out of the ordinary
• Like Oscar and Felix's pairing
• Not quite right
• Freaky
• Not even!
• Unlike this clue number
• With 44-Across, handyman's task