The adjective perplexing describes something it is confusing. Before you're fluent in Arabic, you may find the unfamiliar alphabet to be totally perplexing.
The Latin root of perplexing is perplexus, which means involved, confused, or intricate. This root is also found in the verb perplex, or confuse. Problems are often described as perplexing, especially when several attempts to solve them are unsuccessful. You may have a perplexing decision to make, like where to go to college or whether to stay friends with a fun person who has disappointed you in some way.