Based on tears, new words formed by adding one letter at the beginning or end:
aaerst   breatas   cbarest   dbaster   ebreast   ftabers   gcarets   hcartes   icaster   kcaters   lcrates   mreacts   nrecast   otraces   pdaters   rderats   sstared   ttrades   utreads   varetes   weaster   xeaters   yreseat   zseater