adj

• (predicatively, chiefly in the negative) Lacking peers who share one's beliefs, experiences, practices, etc.
  "Senator Craddock wants to abolish the estate tax, and she's not alone."
• (obsolete) Apart from, or exclusive of, others.
  "There are proofs enough in History, and first that beautiful Hynes, so much beloved by Charles the seventh King of France, who valued the alone possession of her Love at so high a rate, that[…]"
• (obsolete) Mere; consisting of nothing further.
  "and therefore all Killing, Banishing, Fining, Imprisoning, and other such things, which Men are afflicted with, for the alone exercise of their Conscience, or difference in Worship or Opinion, proceedeth from the spirit of Cain, the Murderer, and is contrary to the Truth;"
• (obsolete) Unique; rare; matchless.
  "Pardon me, Proteus, all I can is nothing / To her, whose worth makes other worthies nothing; / She is alone."

adv

• Focus adverb, typically modifying a noun and occurring immediately after it.
  "Her wardrobe is huge. She has three racks for blazers alone."