i keep making mistakes on this one (just started few days ago). WaniKani tells me its barb which is not a very common word in English unless you say barbwire.
I checked some other dictionaries and they usually refer 亅 as a hook. Which is easier to be honest and exactly looks like a hook!
Also 一 is referred as ground in here while many other resources say it is “one” And it is very similar to radicals like two and three… Whenever i see it in test i type “one” and get an error.