Favoring traditional views and values; tending to oppose change. Traditional or restrained in style: a conservative dark suit. Moderate; cautious: a conservative estimate. Of or relating to the political philosophy of conservatism. Belonging to a conservative party, group, or movement. Of or belonging to the Conservative Party in the United Kingdom or the Progressive Conservative Party in Canada. Of or adhering to Conservative Judaism. Tending to conserve; preservative: the conservative use of natural resources. One favoring traditional views and values. A supporter of political conservatism. A member or supporter of the Conservative Party in the United Kingdom or the Progressive Conservative Party in Canada. Archaic A preservative agent or principle.