1:preservative 2 a: of or relating to a philosophy of conservatismbcapitalized: of or constituting a political party professing the principles of conservatism: as (1): of or constituting a party of the United Kingdom advocating support of established institutions (2):progressive conservative 3 a: tending or disposed to maintain existing views, conditions, or institutions :traditionalb: marked by moderation or caution <a conservative estimate>c: marked by or relating to traditional norms of taste, elegance, style, or manners 4: of, relating to, or practicing Conservative Judaism