What is onomatopoeia?
An onomatopoeia is a word that imitates sound. "Onomatopoeic" is often synonymous to "echoic" or "imitative". The plural form is "onomatopoeias" but it can also be used as an uncountable noun. So kaboom and buzz are onomatopoeias, but they also share the property of onomatopoeia. Finally, onomatopoeia can also mean the use of language with words that imitate sound. The word comes from Greek and roughly means "name-making", because the sound makes the meaning. This web site presents over six hundred of them and more are added every day. Onomatopoeia is found everywhere: in poetry, children's books, comics, literature, advertisement, art and on the web.
Etymology
Besides strict onomatopoeia, there are a lot of words that stem from words that were originally imitative, but are no longer in their current form. For example, according to Etymonline, "buffoon" comes from the Italian word "buffare", meaning "to puff out the cheeks," which in the 16th may have been a comic gesture and therefore of echoic origin. Nowadays, buffoon still means "a ridiculous but amusing person; a clown", but we don't associate it with puffing out the cheeks anymore, nor do we find puffing out the cheeks all that hilarious.
Variability
Onomatopoeia for the same thing can vary quite a bit. For example, in Aristophanes' comic play The Frogs (Ancient Greek), the frogs say "brekekekex koax koax" whereas nowadays in English we use "ribbit", although some say they actually imitate a different species of frog!. Spelling can also vary quite a bit. Of interest here is a webpage that shows an analysis of the many different spellings of "Aargh" found on the internet, called The Aargh Page, and it is fascinating.