The term 'strait-laced' originated in the 15th century, initially describing a tightly fastened bodice or corset, literally meaning "laced tightly". The word 'strait' itself evolved from Latin 'strictus', meaning "drawn tight", which is also the root for 'strict'. Over time, the physical constriction of tight clothing became a powerful metaphor for rigid moral and behavioral constraints. By the 16th century, the term had fully acquired its modern figurative sense, describing a person who is excessively strict, narrow-minded, or puritanical in their attitudes, particularly regarding propriety and conduct.

Structure: strait (narrow, strict) + laced (fastened) - strait: From Middle English 'streit', from Old French 'estreit' (narrow, tight), from Latin 'strictus' (drawn tight, compressed). In this compound, it functions as an intensifier meaning "strict" or "tight". - laced: Past participle of the verb 'lace', from Old French 'lacier' (to fasten with a lace or cord). In this compound, it functions metaphorically to mean "fastened" or "bound".