The Collaborative International Dictionary of English v.0.48:

Pappy \Pap"py\, a. [From Pap soft food.]
   Like pap; soft; succulent; tender. --Ray.
   [1913 Webster] Paprika

Moby Thesaurus II by Grady Ward, 1.0:

55 Moby Thesaurus words for "pappy":
   abba, dad, daddy, dead, dilute, diluted, fade, father, flat,
   flavorless, foster father, genitor, governor, gruelly, inane,
   indifferent, insipid, jejune, mild, milk-and-water, mushy, old man,
   pa, pap, papa, pater, paterfamilias, patriarch, pop, pops, pulpy,
   sapless, savorless, sire, spiceless, spongy, squashy, squelchy,
   squishy, squushy, stale, stepfather, tasteless, the old man, thin,
   unflavored, unsavory, vapid, washy, watered, watered-down, watery,
   weak, wishy-washy, yielding