Just one more thing I was thinking about and I wanted to post before I slept.
I was dwelling on what we were talking about and I came up with six different processes which create new words.
I) Naturalisation. This is when you adopt a loanword but you change it to fit the phonetic or grammatical rules of your language.
II) Evolution. This is the gradual shift of sound and form within the same language. So Old Latin oinos becomes Classical Latin ūnus.
III) Inflection. This is when you alter a word using prefixes, suffixes, diminutives, and other grammatical modifiers. It was used heavily by Latin.
IV) Synthesis. This is when you take two words and fuse them together, like cat + girl = catgirl. It’s used heavily by English.
V) Generation. This is when you have a multi-consonantal semantic stem which you enrich with vowels; so, s-l-m becomes salaam.
VI) Invention This is any flexible process by which new base words are “invented” (often based on existing external words to some degree) in conlangs like Interlingua and Esperanto.