Source : Webster's Revised Unabridged Dictionary (1913)

Apron string \A"pron string`\
   The string of an apron.

   {To be tied to a} {wife's or mother's} {apron strings}, to be
      unduly controlled by a wife or mother.

            He was so made that he could not submit to be tied
            to the apron strings even of the best of wives.
                                                  --Macaulay.

Source : WordNet®

apron strings
     n : cord used to tie an apron at the waist [syn: {apron string}]