The word "Screwtape" refers to a fictional character created by C.S. Lewis in his book "The Screwtape Letters". However, there are no synonyms for the word "Screwtape" as it is a proper noun and refers to a specific character. However, there are synonyms for the word "screw". These include words such as twist, tighten, fasten, secure, and clamp. These words all refer to a similar concept of using force to hold something in place or to attach two things together. While there may not be synonyms for "Screwtape", there are many words that can be used to describe his manipulative and deceitful nature such as conniving, scheming, and calculating.