Here are some links.
Check with an idiom dictionary.
You can use an idiom dictionary website such as IdiomSite.
You're more likely to find definitions in a dictionary - there are even idiom dictionaries online.
Body is a word -- it can't be an idiom. You can find many meanings for this word in any good online dictionary.
You really can't most of the time. The whole thing about idioms is that they make no sense if you try to figure them out literally.
That is not an idiom. It means just what it says. You need a medical dictionary to look up medical conditions, not an idiom dictionary. I think by idiom, you may be asking what type of language is represented by the phrase "inflammation of nictitating membrane." That phrase is typical of medical or scientific terminology rather than common or lay language.
Lexicon is not an idiom. It is a word that means either a person's vocabulary, or a dictionary (especially one for Latin, Greek, Hebrew, or Arabic).
The Free Dictionary has one - see link below
"Beg" is not an idiom. An idiom is a phrase that you cannot understand unless you know the definition. "Beg" is a word that you can look up in any dictionary.
what are information can you find in dictionary
You can find a dictionary in a public library, in a bookshop, or online.
top dog, hole, notch, heavy, down, to bottom, spin, look in a dictionary to find the definition of these idioms - and many other examples of top- as an element in an idiom.