fly-by-night (flībī-nīt′) Informal
1. Unreliable or unscrupulous, especially with regard to business dealings: "some fly-by-night startup that was halfway to shutting down" (Douglas Edwards).
2. Of an impermanent or insubstantial nature: fly-by-night fashions in clothing.
n. also fly-by-night·er (-nītər)
1. An unreliable or unscrupulous person.
2. One, such as a company, that is short-lived and therefore unreliable.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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:
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