Don't recall the the name but I believe it is edible.

The first thing you need to know is that it is not a grass but a broadleaf plant. There are selective herbicides which work on most broadleaves and leave the grass unharmed. Weed-b-Gon would be the first thing to try. Weed-b-Gon Chickweed, Clover, and Oxalis Killer would be the thing to try if the first WBG did not work after 3 weeks. If neither one of those works, then RoundUp painted onto individual leaves would work. There is another method to try, but try the WBG first.

This is taking over from last year, north central Texas yard with ‘some’ St. Augustine. Any help identifying and how to kill, kill and kill

Great, so it looks like Dimension should help prevent it and Dicamba should theoretically work for whatever manages to comes up. The Dimension should help fight the stilt grass as well. If too much emerges to pull, fenoxaprop (Bayer crab grass killer) should work. For anyone following along here are some other notes I found on Rutgers site: Do not mix fenoxaprop with the broadleaf weed herbicides, 2,4-D or MCPP, (or apply within 21 days following application of 2,4-D or MCPP or 5 days before 2,4-D or MCPP application. Treated turf should not be mowed within 24 hours of application to allow penetration and translocation into the grassy weeds. Fescues and ryegrass can be reseeded at any time following application of fenoxaprop. Reseeding of all other turf grasses should be delayed at least 21 days after application.