[straight and narrow] n [prob. alter. of strait and narrow; fr. the admonition of Mt 7:14 (AV), "strait is the gate and narrow is the way which leadeth unto life"] (1930): the way of propriety and rectitude--used with the
STRAIGHT AND NARROW
Meaning of STRAIGHT AND NARROW in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012