adj. Of or relating to the showing or giving of preference.
the GNU version of the Collaborative International Dictionary of English
adj. Giving, indicating, or having a preference or precedence
The Century Dictionary and Cyclopedia
Characterized by or having preference; such as to be preferred.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. manifesting partiality
Word Usage
"The Lib Dems are the central backer of the electoral-reform measure, which would dump the U.K.'s longtime voting system—known as "first past the post"—for what is known as a preferential model."