Based on seta, new words formed by adding one letter at the beginning or end:
b - aest c - abets d - baste e - bates f - beats g - betas h - tabes j - caste k - cates l - cesta m - dates n - sated o - stade p - stead r - tsade s - setae t - tease u - fates v - feast w - feats x - fetas y - gates z - getas