The Elastic license doesn’t use the term “competitor”. To me, the definition of the limitation is actually pretty clear:
> You may not provide the software to third parties as a hosted or managed service, where the service provides users with access to any substantial set of the features or functionality of the software.
It doesn't use the word, but "access to any substantial set of the features or functionality of the software as a hosted or managed service" is a specific kind of competition, and who is a competitor can change at any time depending on what functionality Elastic adds, even if you had reimplemented some of the enterprise functionality in a private fork.
Imo "substantial set of features" is pretty ambiguous. If you're using search software, then you have a search use case in your product. At what point does your product cross the threshold into a competitor?
It seems risky to use in anything exposed as a customer facing feature
Search may be 10% of your software but what if your software is a managed email provider (or really anything) and you're pretty much exposing Elasticsearch directly through a minimal interface?
> You may not provide the software to third parties as a hosted or managed service, where the service provides users with access to any substantial set of the features or functionality of the software.
https://www.elastic.co/licensing/elastic-license