Anglish
Anglish is a conlang which seeks to replace foreign borrowed words with native English vocabulary derived from Old English.
For example:
Dictionary > Wordbook
Famous > Nameknown
Native > Inborn
Decide > Choose
Computer > Reckoner
This is achieved by simply choosing to use a native word over a borrowed word, or if there is no modern native word for a given concept, Old English words can be revived and updated to modern spelling and phonology to be used for a modern meaning.
Using the example that YouTuber Rob Words used, here is the preamble to the US Constitution in modern English vs Anglish.
English
"We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America."
Anglish
"We the Folk of the Foroned Riches, to make a more flawless oneship, build rightness, bring frith and stillness to our land, shield one another, uphold the overall welfare, and hold fast the Blessings of Freedom to ourselves and our offspring, do foresay and lay down this lawbook for the foroned riches of Americksland."
History
The term "Anglish" was made up by Paul Jennings in 1966, however the desire to remove foreign influence from the English language is a tradition that goes back all the way to 1066 when the Norman invasion brought in the majority of foreign vocabulary to English.
Many English writers throughout history have spoken out against the use of "Inkhorn Terms" or the needless borrowing of words from foreign languages as a fashion statement.
English scholar, John Cheke, wrote in the 16th century "I am of this opinion that our own tung should be written cleane and pure, unmixt and unmangeled with borowing of other tunges; wherein if we take not heed by tiim, ever borowing and never paying, she shall be fain to keep her house as bankrupt."
William Barnes, a writer and poet from the 19th century, famously called for the removal of Latin, French and Greek vocabulary from English, and promoted Anglo-Saxon substitutes, like wortlore for botany, and welkinfire for meteor.
In the 20th century, William Strunk Jr. wrote in The Elements of Style, "Do not be tempted by a twenty-dollar word when there is a ten-center handy, ready and able. Anglo-Saxon is a livelier tongue than Latin, so use Anglo-Saxon words."
More recently in the 21st century, author David Cowley has released his book called "How We'd Talk If the English Had Won in 1066", among others, that goes into depth on the vocabulary and sound changes that happened to English as a result of Norman influence. Cowley is not the only one making new writings in and about Anglish, there are many online communities from YouTube to Reddit to Discord that generate new Anglish works on a regular basis.