Meaning: The basic meaning of "a" is simply "on".
Pronunciation: "A-" is always pronounced like the "u" in "cup".
Example 1: To be "atop" means "on top" or "on top of". So we can be "atop a mountain". This word is
quite formal, so we may only see it in writing.
Example 2: To go "aboard" means to "get on" a ship, boat or airplane. "I said goodbye to my family,
then it was time to go aboard the airplane".
Example 3: The word "awash" means to have a lot of something all around you, as if you are washing
yourself in water. "After he won the lottery, he was awash in both money and in new friends". (So the money seemed
to be all around him, and so were all the people who wanted to be his friend!)
Other useful words:
ashore - to get off a ship
abroad - to go across the ocean and go to another country
aloft - up in the air
ablaze - on fire
accost - to approach a person in a rude way
amid - in the middle of
anew - try again, or do something in a new way
arise - to get up
await - to wait for something that will surely happen