The Collaborative International Dictionary of English v.0.48:
Demit \De*mit"\, v. t. [imp. & p. p. Demitted; p. pr. & vb. n.
Demitting.] [L. demittere to send or bring down, to lower;
de- + mittere to send. Cf. Demise.]
1. To let fall; to depress. [R.]
They [peacocks] demit and let fall the same [i. e.,
their train]. --Sir T.
2. To yield or submit; to humble; to lower; as, to demit
one's self to humble duties. [R.]
3. To lay down, as an office; to resign. [Scot.]
General Conway demitted his office. --Hume.