Here are some words I made up at various points in my life, for various reasons. Many of them I made up for a class where we learned different Greek roots and had to make our own words from those roots. A few of them are words I've actually used at some point; most of them aren't. In some cases, others have coincidentally come up with the same or similar words as I have, which may or may not have the same meaning.
See also "The Agnographer", a story I wrote back in 2008-ish using many of these words.
This list currently contains
16 abstract nouns,
11 concrete nouns,
4 verbs (including 1 idiomatic verb phrase),
2 taxonomic designations,
1 punctuation mark,
1 pronoun (with 4 distinct forms),
1 suffix, and
Of the words,
24 are from Greek,
20 are from English,
4 are from Latin,
1 is from MyLanguage,
4 are from multiple languages, and
2 are simply made-up.
punctuation mark: used to show the end of a sarcastic sentence, replacing any period that would otherwise go there
(unlike <sarcasm>/</sarcasm>, this doesn't give away the presence of sarcasm before the sentence starts and isn't a mismatched tag; it has the additional advantage that if it's typed in HTML directly (&sarcasm;), it'll appear as written until a sarcasm mark becomes supported by web browsers, at which point it will automatically change.)
colorful thinking[by analogy with black-and-white thinking]
abstract noun: a type of thinking that recognizes that, not only are there points between two extremes, but there are multiple relevant axes (as opossed to black-and-white thinking and grayscale thinking)
cryOlaf /ˌkraɪ ˈoʊ.lɑf/ [from the idiom "cry wolf" + Count Olaf from A Series of Unfortunate Events]
idiom: to repeatedly make true statements that aren't believed, and then be treated as if one has been crying wolf
drogynous /ˈdɹɑ.dʒɪn.ʌs/ [back-formation from androgynous]
adjective: having traits that are clearly, unambiguously, male or female, and not a mix of the two; not androgynous
'e /i/ [Based on the sounds that are in both "he" and "she"]
pronoun: gender-neutral singular pronoun; forms:
(...I don't really like this much anymore, because there are already other pronouns and adding another doesn't help, and because 'e sounds like he in certain dialects and h' sounds like her in certain dialects)
number: 9+2, used in my duodecimal system along with tern, represented by (an H with a vertical line through it)
concrete noun: one who forms words from prefixes, bases, suffixes, like I'm doing here!
(...actually glimorphemician might be more accurate...)
grayscale thinking[by analogy with black-and-white thinking]
abstract noun: a type of thinking that recognizes that there are points between two extremes (as opposed to black-and-white thinking), but fails to recognize that there is more than one relevant axis (as opposed to colorful thinking)
gred /ˈgɹɛd/ [green + red]
adjective: red, yellow, or green (could be used by color-blind people)
(I don't have enough experience with color blindness to know whether such a word would actually be useful.)
-gry /ɡɹi/ [from hungry]
Example: I'm hungry, but I'm not really dinnergry, just snackgry.
pronoun: gender-neutral object or possessive pronoun: him/his, her, or them/their; see 'e
title: used to refer to a married male (for completeness with Miss/Mrs.)
For the married version of Miss, the pronunciation pluralizes Miss and the spelling adds an s onto the opposite gender's title (Mr.), so I did the same to Mr., pluralizing the pronunication of Mr. but pluralizing the spelling of Ms.
onymous /ˈɑ.ˌnɪm.əs/ [Gk. onym "name"; by analogy with anonymous]
scribimency /ˈskɹib.ɪ.mɛns.i/ [Latin scribere "write" + mens "mind", inspired by Harry Potter's legilimency]
abstract noun: the ability to put thoughts into another's mind; mind-writing
(Originally I had encephalograhy, but apparently that word is already in use with a different meaning. Also probably mind-writing would work.)
verb: to divide into six equal parts
noun: an item that has been divided into six equal parts
Plural: sixthseds /ˈsɪksθsts/
tetraperimorph[Gk. tetra "four" + peri "around" + morph "form"]
abstract noun: one of four parts of the perimeter of a 2-dimensional shape, area, or region
Example: a bay is a body of water surrounded by land on three tetraperimorphs. Inspired by the definition of bay I heard in fourth grade, "body of water surrounded by land on three sides", which logically should include triangular lakes.
number: 9+1, used in my duodecimal system along with elefator, represented by ∀ (an upside-down A)
I used the symbols, but not the names, in Súiⱥcúili. This is a homonym of a type of a bird.
univorous /ju.ˈnɪv.ɚ.əs/ [Latin uni "one" + vore "eat"]
Can be used gramatically wherever not can be used. Yest does not change the meaning of the sentence when taken out, but it can be used for clarity ("Did you say can or can't"/"I can yest do it"), contrastive focus, or parallel structure (e.g., "Did not"/"Did yest"/"Did not"/"Did yest"/etc.).