brightline

or bright-line

[brahyt-lahyn]
|

adjective

(of rules, standards, etc.) unambiguously clear: This muddies the waters of what should be a brightline rule.

noun

Physical Chemistry. brightline spectrum.

Origin of brightline

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for bright-line

Historical Examples of bright-line