Doubler antonyms

What is the opposite word for Doubler?

• decrease

  make two of
• diminish

  make two of
• singular

  in a pair
• single

  in a pair
• original

  something which exactly resembles another
• lessen

  make two of
• abridge

  make two of
• compress

  make two of
• condense
• curtail
• halve
• reduce
• divide
• disect