When one considers Indo-European languages, especially those which are
properly European, one can perceive that there are many similarities among
them. These similarities surely are due to their roots in the very distant
past of civilized mankind, going back to the early Sanskrit language.
With the exception of a few cases, modern words for things, feelings,
beings and thoughts that are very primitive, basic, ancient, well known
and easily perceived by mankind are very simple and quite short.
Those words are nowadays short and simple and they were probably also
that short since their ancient origin.
Even considering that most of the words in European languages with either
simple or sophisticated meanings, are monosyllabic or bisyllabic, there is
some pattern that confirms that nouns for well known things are generally
That perception is easy, even without any further deeper research.
Why are such word short? This seems quite obvious: first things comes first.
Primary languages first used most of possibilities of monosyllabic or bisyllabic
sounds. When most sophisticated and complicated subjects required new words,
there were few possibilities left for monosyllabic or bisyllabic words. So
longer words were necessary.
Another easily realized language pattern, that has also obvious roots, is
that there are more differences among words with the same meaning in different
languages for ancient and traditional stuff, than for very recent, modern,
technological, medical, nouns.