The Collaborative International Dictionary of English v.0.48:

Dandriff \Dan"driff\ (d[a^]n"dr[i^]f), n.
   See Dandruff. --Swift.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dandruff \Dandruff\ (d[a^]n"dr[u^]f), n. [Prob. from W.
   toncrust, peel, skin + AS. dr[=o]f dirty, draffy, or W. drwg
   bad: cf. AS. tan a letter, an eruption. [root]240.]
   A scurf which forms on the head, and comes off in small
   scales or particles. [Written also dandriff.]
   [1913 Webster]