The Collaborative International Dictionary of English v.0.48:
Vacant \Va"cant\, a. [F., fr. L. vacans, -antis, p. pr. of
vacare to be empty, to be free or unoccupied, to have
leisure, also vocare; akin to vacuus empty, and probably to
E. void. Cf. Evacuate, Void, a.]
1. Deprived of contents; not filled; empty; as, a vacant
Stuffs out his vacant garments with his form.
Being of those virtues vacant. --Shak.
There is no fireside, howsoe'er defended,
But has one vacant chair. --Longfellow.
2. Unengaged with business or care; unemployed; unoccupied;
disengaged; free; as, vacant hours.
Religion is the interest of all; but philosophy of
those . . . at leisure, and vacant from the affairs
of the world. --Dr. H. More.
There was not a minute of the day which he left
vacant. --Bp. Fell.
3. Not filled or occupied by an incumbent, possessor, or
officer; unoccupied; as, a vacant throne; a vacant house;
a vacant apartment; a vacant parish.
[1913 Webster +PJC]
Special dignities which vacant lie
For thy best use and wearing. --Shak.
4. Empty of thought; thoughtless; not occupied with study or
reflection; as, a vacant mind.
The duke had a pleasant and vacant face. --Sir H.
When on my couch I lie
In vacant or in pensive mood. --Wordsworth.
5. (Law) Abandoned; having no heir, possessor, claimant, or
occupier; as, a vacant estate. --Bouvier.
Vacant succession (Law), one that is claimed by no person,
or where all the heirs are unknown, or where all the known
heirs to it have renounced it. --Burrill.
Syn: Empty; void; devoid; free; unemployed; disengaged;
unincumbered; uncrowded; idle.
Usage: Vacant, Empty. A thing is empty when there is
nothing in it; as, an empty room, or an empty noddle.
Vacant adds the idea of having been previously filled,
or intended to be filled or occupied; as, a vacant
seat at table; a vacant office; vacant hours. When we
speak of a vacant look or a vacant mind, we imply the
absence of the intelligence naturally to be expected
Bouvier's Law Dictionary, Revised 6th Ed (1856):
VACANT SUCCESSION. An inheritance for which the heirs are unknown.