straight / strait
Not bent, versus a narrow passage.
Straight means not bent, or direct. A strait is a narrow channel joining two larger bodies of water, and the plural straits means hardship: dire straits. An old adjective strait, meaning tight or strict, survives in straitjacket and straitlaced.
Examples
Use Sea ice covers the Bering Strait for much of the winter.
Use After the mill closed, the town was in dire straits.
Use The escape artist wriggled out of a straitjacket in under a minute.
Avoid After the mill closed, the town was in dire straights. (Change straights to straits.)
Avoid The escape artist wriggled out of a straightjacket in under a minute. (Change straightjacket to straitjacket.)