Englishfor English speakers
online
Preposition
—
If a system is online, it is connected (generally electronically) to a larger network.
I do a lot of shopping online, so I almost never have to leave the house.
—
If a machine is online, it is turned on and is ready to do work.
Since the printer is back online, you should be able to again print from it.
dictionary
Noun
—
A dictionary is a book that tells you what words mean, and how to spell them. A lot of dictionaries will also tell you about etymology (where words come from) and pronunciation (how to speak them).
You are reading an online dictionary right now.
The words in a printed dictionary are in alphabetical order.
I looked up the dictionary to find the meaning of the word business.