Lynguistykon: Language
Language is how living beings communicate, combining words and usually intonations to record or transfer meaning. How those words and intonations present themselves varies very widely among species, cultures, and even individuals. Language can be audibly, visually, or otherwise sensorily communicated. Language can be the means by which a living being communicates internally, as well.
Words
Communication usually involves many words put together to communicate a complete idea or multiple ideas together. A word is a recognizable communication holding an idea/meaning, that can thereby be transferred. A morpheme is likewise a recognizable communication holding an idea/meaning that can thereby be transferred, but it is the smallest unit of language that still does so. So all morphemes are words, but not all words are morphemes, since a word can also be composed of multiple morphemes. Similarly, depending on the language a letter may already essentially serve as a morpheme/word with a basic identifiable meaning that stands on its own (which can then be combined with other letters to present deeper or altered meanings), or letters may only serve as building blocks and convey sufficient meaning combined together with other letters to form morphemes/words. Note that in many languages, although all morphemes carry identifiable meaning, not all morphemes are used standalone as words due to linguistic conventions.
Intonation
Intonation is attached to letters/words to either deeper or alter their meaning.
Writing
Writing is the recording of language visually in a way that meaning can be facilely retrieved from later. Many different systems of writing exist for languages, but the Lynguistykon and other written works related to Somewhere Else usually use a uniform system of writing in general in order to be accessible.