Searching string array using Query.contains

Hey I need to search a string array for a keyword, and I think contains is the only method to do that. The problem is it that its extremely hit or miss. In testing, it will reliably work with one full word example "play", but then won't find multiple instances of "dance". Additionally, its case sensitive which is another problem as Play will not find play and vice versa. Am I missing something? Is there a better solution? I need to be able to look up documents like this.