I am looking for a term that describes an acronym that has two possible expansions, but both expansions refer to the same thing. The term "double acronym" doesn't appear to be widely used and is confusing. Some examples:
In human-computer interaction, there is a single tool called CPM-GOMS, where the CPM stands for both "cognitive, perceptual, motor" and "critical path method".
Additionally, a popular cognitive modeling tool called ACT has both "Atomic Components of Thought" and "Adaptive Character of Thought" as its meanings.
In both cases, these are not two distinct tools that coincidentally share the same acronym. They are acronyms that purposefully have two distinct expansions that refer to the same tool.
The usage might also apply to companies who have changed the words in their acronym while keeping the original initialism, such as:
However in these cases one expansion is clearly non-standard. There are also unofficial acronyms, such as DVD, which appears to be used equally as "digital video disc" and "digital versatile disc", despite that neither is standard.
It may also apply to translations in which the initialism is preserved, such as the car company BMW which stands for Bayerische Motoren Werke AG, but is often written as Bavarian Motor Works.
There is no wikipedia for "double acronym" and < 6,500 google results for the same search term. Is there a standard term for this usage that I am not aware of? If not, what short phrasing could be best used to describe this usage? Note I am primarily interested in a phrase that captures the first usage (e.g. CPM and ACT).
Best Answer
This doesn't happen often enough for there to be a single word, or even a standard phrase.
However, as Mitch suggested, ambiguous means:
Therefore ambiguous acronym is a good match.
However, remember an acronym is usually an initialism or abbreviation pronounced as a word, like NASA, radar, laser and ACT, unlike BBC and CPM.
So ambiguous abbreviation is a more general term.