WordNet (r) 3.0 (2006):

tight-laced
    adj 1: exaggeratedly proper; "my straitlaced Aunt Anna doesn't
           approve of my miniskirts" [syn: priggish, prim,
           prissy, prudish, puritanical, square-toed,
           straitlaced, strait-laced, straightlaced,
           straight-laced, tight-laced, victorian]