以前、アメリカ人の「英熟語は日本語の熟語とまったくちがう」という言葉に驚かされた事を思い出します。当時の私の認識では、イディオムも複合語も「英熟語」でした。
ですが、日本でも
三省堂提供「大辞林 第二版」より
成句 (2)に該当
(1)昔から多くの人に知られ、しばしば引用される名句やことわざ。成語。
「故事―」
(2)二語以上の語が習慣的に結び付いて、ある決まった意味を表す言い回し。「襟を正す」などの類。慣用句。
複合語
〔compound word〕単語のうち、意味・語形の上から二つ以上の単語の結合によってできたと認められる語。「朝日」「買い物」「花見」「祝い酒」「書き込む」の類。合成語。熟語。〔「さかな」「なべ」など複合意識の一般に薄れてしまった複合語も多い〕→単純語
idiom : 成句、慣用句
http://www.bartleby.com/59/7/idiom.html
A traditional way of saying something.
Often an idiom, such as “under the weather,” does not seem to make sense if taken literally. Someone unfamiliar with English idioms would probably not understand that to be “under the weather” is to be sick.
compound word : 複合語
http://www.bartleby.com/64/84.html
A COMPOUND word is made up of two or more words that together express a single idea. There are three types of compounds.
An open compound consists of two or more words written separately, such as salad dressing, Boston terrier, or April Fools’ Day.
A hyphenated compound has words connected by a hyphen, such as age-old, mother-in-law, force-feed.
A solid compound consists of two words that are written as one word, such as keyboard or typewriter.
In addition, a compound may be classified as permanent or temporary. A permanent compound is fixed by common usage and can usually be found in the dictionary, whereas a temporary compound consists of two or more words joined by a hyphen as needed, usually to modify another word or to avoid ambiguity. In general, permanent compounds begin as temporary compounds that become used so frequently they become established as permanent compounds. Likewise many solid compounds begin as separate words, evolve into hyphenated compounds, and later become solid compounds. Although the dictionary is the first place to look when you are trying to determine the status of a particular compound, reference works do not always agree on the current evolutionary form of a compound, nor do they include temporary compounds. The following general rules apply to forming compounds. Keep in mind that words that are made up of a word root plus a prefix or a suffix are not normally considered compounds, strictly speaking. But for convenience we discuss them here since they are also sometimes hyphenated.
お礼
ありがとうございました、今後とも、よろしくお願いします!