The best way to ask about synonyms on ELU is to make sure you include:
Dictionary definitions of the words you are asking about (i.e., give us all a baseline to work from in the question itself; don't make us all go look up the words in the dictionary as part of our analysis).
The reason that you're asking about those particular words. (Did you find them in a book? Are you writing a paper? If so, what is the paper for?)
As an example, I think the words milky and creamy could be considered synonymous in some contexts:
milky (adj.)
containing or mixed with a large amount of milk : a cup of sweet milky coffee.
• resembling milk, esp. in color : not a blemish marred her milky skin.
• (of something that is usually clear) cloudy : the old man's milky, uncomprehending eyes.
creamy (adj.)
resembling cream in color or consistency : creamy white flowers | beat the sugar and egg yolks together until thick and creamy.
• containing a lot of cream : a thick, creamy dressing.
So, if you were to ask a question like this:
Milky vs. Creamy
Do milky and creamy mean the same thing?
or even:
Milky White or Creamy White?
When should I use milky vs creamy? Are they the same color?
then I think you'd be (rightfully) hit with a lot of comments, asking, "What does the dictionary say?" or, "Sometimes they do, and sometimes they don't; more context please."
But, if you said instead:
Milky White vs. Creamy White
I noticed that, in the dictionary, both milky and creamy can mean resembling milk (or cream) in color. NOAD says:
- milky (adj.) resembling milk, esp. in color
- creamy (adj.) resembling cream in color
and I'm writing about a room that was recently painted. I'm considering saying that the room is creamy white, or milky white. I would like to know:
(1) Is there a difference between those two? Would you imagine that a creamy white room is a slightly different color than a milky white room? (I typed "creamy white room" and "milky white room" into a Google image search, but the rooms looked pretty much the same color).
(2) Both of these words have other meanings (for example, creamy can mean "resembling cream in consistency;" milky can mean "cloudy, said of something that is usually clear, such as milky, uncomprehending eyes). If milky white and creamy white are essentially the same color, is there any reason I should avoid using one word or the other, because of some other meanings of the word?
Now, no one can say you haven't done any research (clearly you have), and no one can say there is not enough context (because it's abundantly provided). Furthermore, no one can ask why the question is relevant (you've explained that – you're writing about a recently painted room). I would wager that such a question would get both helpful answers and upvotes.
So, yes, questions about differences in meaning are welcome on ELU. However, it is vital to include sufficient detail in your question so that (a) it can be answered without requests for further clarification, and (b) it is evident that you haven't come to ELU before consulting readily available resources, such as a dictionary and search engine.
One last tidbit of advice
If you do ask a question, and someone in the community asks you something like, "Did you look at a thesaurus? What did you find there?" then do not answer that comment with another comment; instead, edit your question.
Here's an example; suppose you asked:
Another word for burning eyes
I was trying to describe an itchy, burning sensation in my eyes, but I don't like the word burning, because that brings to mind the eyeballs being on fire. What other word can I use?
And the first response was a comment, asking:
Did you look in a thesaurus? What did you find?
If you didn't look in a thesaurus, that would be a good time to go do so. But maybe you had looked in a thesaurus. Your first instinct might be to leave a comment like this:
Yes I did, but I didn't find anything suitable there.
I don't think that's a good idea, though. Why? If one user asked about a thesaurus, others will probably wonder about the same thing. So, a better thing to do would be to edit your question, showing your research to the rest of the community such that they can see it, without reading through all the comments underneath the question. Hence, your edited question might now look like this:
Another word for burning eyes
I was trying to describe an itchy, burning sensation in my eyes, but I don't like the word burning, because that brings to mind the eyeballs being on fire. What other word can I use?
I tried looking up burning in a thesaurus, but all the words there either had the same connotation of being literally on fire (such as flaming, fiery, glowing, smoldering, red-hot, fiery, blistering, scorching, searing, roasting, sizzling), or else they were words describing emotions, like being in love (e.g., passionate, ardent, fervent, urgent, fierce, eager, frantic, consuming, uncontrollable). None of these words seem to fit as a good alternative to burning, not when describing "itchy, burning eyes."
Do you see where that brings you, now that you've revised the question? Once again, it's hard for anyone to question your research; plus, it's easier for everyone to understand the context. I think that question – in its revised form – would receive both upvotes and helpful answers. Without that revision, though, most of the upvotes would probably go to the comment asking you, "Did you look in a thesaurus?"
In short, it's not just about what you ask, it's also about how you ask.