Antonyms of adj straight-laced

1 sense of straight-laced

Sense 1
priggish, prim, prissy, prudish, puritanical, square-toed, straitlaced, strait-laced, straightlaced, straight-laced, tight-laced, victorian -- (exaggeratedly proper; "my straitlaced Aunt Anna doesn't approve of my miniskirts")

INDIRECT (VIA proper) -> improper -- (not suitable or right or appropriate; "slightly improper to dine alone with a married man"; "improper medication"; "improper attire for the golf course")
                                                                         

Similarity of adj straight-laced

1 sense of straight-laced

Sense 1
priggish, prim, prissy, prudish, puritanical, square-toed, straitlaced, strait-laced, straightlaced, straight-laced, tight-laced, victorian -- (exaggeratedly proper; "my straitlaced Aunt Anna doesn't approve of my miniskirts")
       => proper (vs. improper) -- (marked by suitability or rightness or appropriateness; "proper medical treatment"; "proper manners")