Anti-conservative

disposed to preserve existing conditions, institutions, etc., or to restore traditional ones, and to limit change.
cautiously moderate or purposefully low:
a conservative estimate.
traditional in style or manner; avoiding novelty or showiness:
conservative suit.
(often initial capital letter) of or relating to the Conservative party.
(initial capital letter) of, relating to, or characteristic of Conservative Jews or Conservative Judaism.
having the power or tendency to or preserve.
Mathematics. (of a vector or vector function) having curl equal to zero; irrotational; lamellar.
a person who is conservative in principles, actions, habits, etc.
a supporter of conservative political policies.
(initial capital letter) a member of a conservative political party, especially the Conservative party in Great Britain.
a preservative.
adjective
favouring the preservation of established customs, values, etc, and opposing innovation
of, characteristic of, or relating to conservatism
tending to be moderate or cautious: a conservative estimate
conventional in style or type: a conservative suit
(med) (of treatment) designed to alleviate symptoms Compare radical (sense 4)
(physics) a field of force, system, etc, in which the work done moving a body from one point to another is independent of the path taken between them: electrostatic fields of force are conservative
noun
a person who is reluctant to change or consider new ideas; conformist
a supporter or advocate of conservatism
adjective, noun
a less common word for preservative
adjective (in Britain, Canada, and elsewhere)
of, supporting, or relating to a Conservative Party
of, relating to, or characterizing Conservative Judaism
noun
a supporter or member of a Conservative Party
adj.

late 14c., conservatyf, from Middle French conservatif, from Late Latin conservativus, from Latin conservatus, past participle of conservare (see conserve).

As a modern political tradition, conservatism traces to Edmund Burke’s opposition to the French Revolution (1790), but the word conservative is not found in his writing. It was coined by his French disciples, (e.g. Chateaubriand, who titled his journal defending clerical and political restoration “Le Conservateur”).

Conservative as the name of a British political faction first appeared in an 1830 issue of the “Quarterly Review,” in an unsigned article sometimes attributed to John Wilson Croker. It replaced Tory (q.v.) by 1843, reflecting both a change from the pejorative name (in use for 150 years) and repudiation of some reactionary policies. Extended to similar spirits in other parties from 1845.

Strictly speaking, conservatism is not a political system, but rather a way of looking at the civil order. The conservative of Peru … will differ greatly from those of Australia, for though they may share a preference for things established, the institutions and customs which they desire to preserve are not identical. [Russell Kirk (1918-1994)]

Phrases such as a conservative estimate make no sense etymologically. The noun is attested from 1831, originally in the British political sense.

conservative con·ser·va·tive (kən-sûr’və-tĭv)
adj.
Of or relating to treatment by gradual, limited, or well-established procedures; not radical.
con·ser’va·tive·ly adv.

A descriptive term for persons, policies, and beliefs associated with conservatism.