thing

Concise Oxford English Dictionary © 2008 Oxford University Press:
thing/θɪŋ/

▶noun

• 1 an object that one need not, cannot, or does not wish to give a specific name to.

  ■ (things) personal belongings or clothing.

• 2 an inanimate material object as distinct from a living being.

  ■ a living creature or plant.

  ■ a person or animal in terms of one's feelings of pity, approval, etc.: you lucky thing!

• 3 an action, activity, concept, or thought.

  ■ (things) unspecified circumstances or matters.

• 4 (the thing) informal what is needed or required.

  ■ what is socially acceptable or fashionable.

• 5 (one's thing) informal one's special interest or concern.

– phrases
be hearing (or seeing) things imagine that one can hear (or see) something that is not in fact there.
a close (or near) thing a narrow avoidance of something unpleasant.
do one's own thing informal follow one's own inclinations regardless of others.
have a thing about informal have a preoccupation or obsession with.
there is only one thing for it there is only one possible course of action.

– origin OE (also in the senses ‘meeting’ and ‘matter, concern’), of Gmc origin.