|part of speech:
||any one of a group or kind.
Do you have a computer?Somebody call a doctor!A penguin cannot fly.Could you get me a spoon from that drawer?
||one, as a quantity.
I've told you that a hundred times.Add a teaspoon of cinnamon.
||one; used to introduce one particular thing of a group or kind, but one which is not known to the listener or is not important to identify.
A friend of mine called from London last night.They bought a new car.I have a brother who two years older than I.