well, look at the other part, it says ground lion. As if there were a tree lion? of corse, chameleons would make a good tree lion. i just think it is odd that is says "ground lion", because chameleon are tree dwellers.
The word "Chami" can be translated a couple ways. Either geo which would "mean world or earth." Geo could also be taken to mean on the ground. "Leo" really no disagreement that this is lion. Now if you have a veiled the scientific name could mean a couple things also, Chamaeleo Calyptratus. Calyptratus could be taken to mean "with helmet" or "with crown". I personally like the name "Earth lion with crown" for the veiled.
As for lions in general they can climb trees. Now once they mature most will never do this unless necessary. I guess the rewards for climbing a tree when you are that big are limited. If a large pack of hyenias comes into play some lions will go up into trees for protection. Once hyenias get 4:1 ratios against lions they will in fact attack them and at times win. Most lions know this and will retreat either from a carcass or for their own lives.
Most scientific names have roots that describe the species and once you understand a lot of the common roots, you will often know something about the species simply by hearing the scientific name. For example: quadricornis is a reference to their four horns; laterispinis means lateral spines; spinosus is a reference to all the spines on the body; melanocephalum means black head, etc.
I have some pictures I found on the net. These are all sub adults from the looks of them.
The referances to lions versus hyenias are from several shows I have watched about the two. I will try to find some links if you are interested.