Learn how to say Strait-Laced correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word strait-laced:
having or showing very strict moral attitudes:
his strait-laced parents were horrified
As an adjective strait means ‘narrow or cramped’ and ‘strict or rigorous’: the idea behind strait-laced and straitjacket is of being tightly laced or confined. As strait is now old-fashioned and unfamiliar, however, people often interpret it as the more usual word straight. Straight-laced and straightjacket are now generally accepted in standard English, and the spelling straight-laced is more common than strait-laced in the Oxford English Corpus.
Strait-laced can also be spelled straight-laced: both are correct.