Toki Pona and its semantic power
Toki Pona is a minimalist conlang with only 14 letters/sounds and 123 words.
The introduction or suppression of any of those words was huge implications upon the semantic network between the different terms.
But in its short history, there have been words that have disappeared or have been accepted into its lexicon for a short while before exiting it again.
kipisi, to cut and monsuta, a monster are two generally known but non-official words.