adj

• (obsolete) Mere.
  "I know some who wittingly have drawne both profit and preferment from cuckoldrie, the only name whereof is so yrksome and bail-ful to so many men."

adv

• (British) Used to express surprise or consternation at an action.
  "She's only gone and run off with the milkman!"
• (obsolete) Above all others; particularly.
  "his most only elected mistress"

conj

• (informal, clause-initial) Introduces a clause with negative polarity, often one which upsets the listener's expectations.
  "You're welcome to borrow my bicycle, only please take care of it."
• (informal, clause-initial) Introduces a clause with negative polarity, often one which upsets the listener's expectations.
  "I would enjoy running, only I have this broken leg."

particle

• (Singapore, Singlish) Placed at the end of a sentence to emphasize that something is trivial, small, undemanding or deserving of belittlement.
  "Just need to replace the filter only."