Learn Hardcore Korean: i daneoui olbareun uimireul sajeone chajaboseyo. - Please look up the correct meaning of this word in the dictionary.

이 단어의 올바른 의미 literally means “the correct meaning of this word.”
If you used 을/를 (the object marker) on 이 단어, you’d be marking “this word” itself as what you look up, not its meaning.

What does 올바른 mean in this sentence?

올바른 means correct, proper, or right.

It modifies 의미 (“meaning”) to stress that you should find the most accurate or appropriate definition.
You could also use 정확한 (“precise”) for a slightly different nuance: 이 단어의 정확한 의미를 사전에 찾아보세요.

Can we use 뜻 instead of 의미 here?

Yes. Both 뜻 and 의미 translate to “meaning,” but:

의미 is a bit more formal or abstract.
뜻 is everyday language.
So 이 단어의 올바른 뜻을 사전에 찾아보세요 is perfectly natural in conversation.

Why is it 사전에 rather than 사전에서, and can I use both?

사전에 (사전 + 에) marks “in/at the dictionary” as the target location.
사전에서 (사전 + 에서) emphasizes the action happening “in the dictionary.”
Both are grammatically correct here:
• 사전에 찾아보세요 (“look up in the dictionary”)
• 사전에서 찾아보세요 (“please look up [it] at/in the dictionary”)
The nuance is minimal; 사전에 is slightly more concise.

Does the word order of 사전에 and 이 단어의 올바른 의미를 matter?

Korean word order is relatively flexible, but the default is Subject–Adverbial–Object–Verb. You can say either:

이 단어의 올바른 의미를 사전에 찾아보세요.
사전에 이 단어의 올바른 의미를 찾아보세요.
Both mean the same thing. Place 사전에 before the object to emphasize the location.

What does the ending -아/어 보세요 add to 찾다?

The suffix -아/어 보다 has two functions here:

It forms a compound verb 찾아보다, meaning “to look up” (e.g., in a dictionary).
As an imperative ending -보세요, it adds the nuance “try doing” something.
So 찾아보세요 = “please try looking up (it).”

Why not just say 찾으세요 instead of 찾아보세요?

찾으세요 comes from 찾다 and simply means “find/look for.”
찾아보세요 specifically means “look up” (with the nuance of searching in a reference) and politely invites the learner to attempt it.
In the context of a dictionary, 찾아보세요 is the standard phrasing.

What level of politeness does -세요 convey, and can I use -십시오?

-세요 is the polite informal (honorific) imperative, suitable for most learning materials or friendly instructions.
Alternatives:

-십시오 – very formal/polite (e.g., 찾아보십시오)
-아/어라 – informal familiar (e.g., 찾아봐라)
Choose based on your relationship with the listener and the formality of the situation.

Can I omit 사전에? If so, does the meaning change?

Yes. 이 단어의 올바른 의미를 찾아보세요 still means “please look up the correct meaning of this word.”

Omitting 사전에 makes it less specific about where to look (dictionary, online, etc.).
If context already implies “in the dictionary,” you can leave it out for brevity.

Is it okay to say 딕셔너리 instead of 사전?

While 딕셔너리 (Konglish) is understood in casual speech, 사전 is the standard Korean word.

In formal writing or teaching, always use 사전.
In a relaxed conversation, you might hear 딕셔너리에 찾아보세요, but it’s stylistically less pure.