Hi.
I am not sure if you already figured it out, but,
I know two easy ways of getting KO names/descriptions and use them afterwards to map their names to the respective KO IDs.
1 - The elegant way: Get title
- If you happen to have a list of KOs, you can map their names using
the lower field at "KO (KEGG ORTHOLOGY) Database" page
(https://www.genome.jp/kegg/ko.html); enter your IDs (separated by
either new lines, spaces, or both) and click "Get title":

- This opens a new browser tab with the KOs description/names:

2 - The not-so-elegant way: Copy from page
If you wish to get all the descriptions/names from once, open the "KEGG
Orthology (KO)" link in the "KO (KEGG ORTHOLOGY) Database" page
(https://www.genome.jp/kegg/ko.html):

Click in the rightmost arrow at top of the list (wait the
complete page load):

Then copy everything! it may lag a litle because the page is a bit heavy (55k+ lines, currently)

Now you can paste in a text file (in my example I used notepad++, but any
other text editor should work):

- Save as tab-delimited file or any other usefull format and get
whichever description you want.
Tips
1 - Avoid using excel IF you are not REALLY sure excel won't mess up the entered data.
If you are REALLY sure it is ok, you can open the file as a speadsheet and use it as a database in formulas like VLOOKUP to map the descriptions to any KOs list you have (comment if you need me to show you how).
2 - In unix systems, you can easily get the description from the text file using grep, awk, sed, etc. This is much better if you wanna map the descriptions within a script/pipeline/program, etc.
I'm glad if this answer helps anyone.
Cheers