1479: Envelope and Lexical Stress Dec 30, 2018
In some words like 'rebel' or 'isolate', the accentuation changes from noun to verb. This is true of 'envelop' and 'envelope'; the only real difference between it and the earlier examples is that the spelling is also different, but the fact that as a verb the stress is at the end yet as a noun it comes at the start. However, the meaning of 'envelope' is not as broad as its counterpart, and really just relates to letters and packaging. This has only been true since the 18th century though, and beforehand it just related to anything that was enveloping.
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