Both Uses of

vagrant
in
Middlemarch

Poor Rosamond's vagrant fancy had come back terribly scourged—meek enough to nestle under the old despised shelter.†
Chpt 8 *

vagrant = someone who is poor and has no regular home or job

But her vagrant mind must be reduced to order: there was an art in self-discipline; and she walked round and round the brown library considering by what sort of manoeuvre she could arrest her wandering thoughts.†
Chpt 8

Definitions:

(1) (vagrant)
someone who is poor and has no regular home or job
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Less commonly, and especially long ago, you may see vagrant used to emphasize that a poor person wanders from place to place. Even more rarely, it can describe an animal as being in a place it usually is not, or to describe anything that varies or seems random such as the seeming haphazard direction in which a certain weed spreads, or the fleeting quality of something smelled for only an instant.