[Middle English, from mid, middle; see MID1.]
Usage Note: Many compounds other than those entered here are formed with mid-. In forming compounds, mid- is normally joined to the following word or element without a space or hyphen: midpoint. If the second element begins with a capital letter, it is separated with a hyphen: mid-May. It is always acceptable to separate the elements with a hyphen to prevent possible confusion with another form, as, for example, to distinguish mid-den (the middle of a den) from the word midden. Note that the adjective mid1 is a separate word, though, as is the case with any adjective, it may be joined to another word with a hyphen when used as a unit modifier: in the mid Pacific but a mid-Pacific island.
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Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.