I gave you the exact breakdown of the ways the terms “chastity” and “chaste” are used theologically.
That Webster cites a popular and limited use, one that I pointed out is common but misleading, is fine. Webster attempts to be descriptive of how words are used.
If you consult the Catechism of the Catholic Church, Thomas Aquinas, the Church Fathers etc. you’ll find that “chaste marital sexual relations” has a long and distinguished history.
I'll take Webster's definition over your interpretation of Church dogma.
The vast majority of Americans, while Christian, are not Catholic.
While I am Catholic, I am also American and live in the popular and limited world, just as Jesus did, and I use the popular and limited definition of my mother tongue.
Definitions that are wide open to interpretation are, for all practical purposes, not definitions at all.