Straight and strait are homophones (“one of two or more words pronounced alike but different in meaning or derivation or spelling”), and many people are in the habit of confusing such creatures, particularly when used in fixed phrases. If you express no emotion you have a straight face; an upright person is a straight shooter; a straight flush is “a poker hand containing five cards of the same suit in sequence.” However, if you find yourself in a difficult situation you are in dire straits. Straitjacket and straitlaced are the more commonly used forms for the restrictive garment and the “strict in manners” adjective, although straightjacket and straightlaced are also occasionally found.