Unknown words

What is the best way to deal with a word where you can’t find the definition? Since the recent changes, blue words change to yellow immediately when you go to search for a definition. If I can’t find a definition in any of my dictionaries, I’m stuck with a yellow word. I’m a bit confused what to do at this point. I’ve been doing one of the following:
a) add a tag (asktutor)
b) put ??? as the definition
c) leave the definition blank

What is the recommended way to deal with this?

Hi, Which word is it ? Else you can erase the yellow word and select it at new for having a blue word …

I will typically click the Ignore x for the word and move on.

If I erase the yellow word (by pressing X), then if that word shows up in future it is ignored, and shown as normal text, not underlined and not highlighted.
At that point I can reselect the word with a mouse and add it again I guess.