Related Clues:

• It can come after no one or someone
• It divided Martin from Lewis
• Arithmetic sign
• Addendum conjunction
• '___ bad'
• Popular joiner
• Ultimatum end
• Last word of an ultimatum, perhaps
• ''Do it, or ___!''
• ''The Sun __ Rises''
• Something extra
• Where starter
• ''Or ___!''
• See 21 Across
• Petite opposite, sizewise