The term "Toot Uncommon" is not a common term, so it is unlikely that you would find it in a text search on your iPhone. However, if you did find it, it could be referring to a number of things.
One possibility is that it is a reference to the social media platform Mastodon, which uses the term "toot" to refer to a post. Mastodon is a decentralized social network, which means that it is not controlled by a single company. This makes it a more privacy-friendly alternative to other social media platforms like Twitter.
Another possibility is that "Toot Uncommon" is a reference to a rare bird species. The common tern is a small seabird that is found in many parts of the world. However, there are also a number of rare tern species, such as the black tern and the royal tern. If you are interested in birds, you may have seen the term "Toot Uncommon" used to refer to one of these rare species.
Finally, it is also possible that "Toot Uncommon" is simply a random string of words that does not have any particular meaning. If you are not sure what it means, you can try searching for it online or asking someone who might know.