orthohawk:
It also has the nasty effect of giving yet another vocabulary word to learn for E-o students, which puts us one further step towards destroying one of the advantages to Esperanto. This attitude prevailing, we may as well just switch to Interlingua cum Esperanto grammar.

That is exactly right. Which is why I use malĝoj-, even though I like trist- better.

LionsAreUs:
OK, forigi translates as "remove", no biggie.
"Triston" looks suspiciously like "sadness" or "sorrow". Strip away the accusative ending, gets you "tristo", which would be a noun, probably "sadness". But type "tristo" into the Google or Lernu translators, and "tristo" gives a null result.

Trista, tristo and tristeco are listed in the Plena Ilustrita Vortaro (vortaro.net) which you can log into with your Lernu ID. Trista is also listed in Wiktionary (en wiktionary.org or eo.wiktionary.org)

Google Translate and Lernu may not be the best places to look up individual words, but you can find example sentences of words in use by using the main Google search page. For example entering the search term +esperanto +tristo found "Ĝojo ne eternas, kun tristo alternas."

Words like trista, liva and frida are used by poets, songwriters, and by some people who just don't like the mal- words.