Old Chemistry and Metallurgy. Free from corrosive salt, sulphur, acid, etc. In modern use also in the Oil Industry, of petroleum or natural gas…

Of a medicine or chemical agent: acting rapidly. Cf. sense A. 2. Obsolete.

Of a solution or decoction: made with water; aqueous. Now rare.

(un-, prefix1 affix 2.)

said of chemical substances which absorb with avidity. ? Obsolete.

Not neutralized, not rendered neutral.

(un-, prefix1 affix 1b.)

Chemistry. Designating a radical, bond, or other entity which is not in chemical combination and is therefore available to interact with other…

Of acids and oils: That cannot be distilled or evaporated without decomposition.

In extended use: that is in the act or condition of coming into existence; beginning to form, grow… Of a material thing or substance: in the act or…

Chemistry. Of elements, compounds, etc.: Not entering into the composition of organized bodies; not formed under the action of the vital forces.

That may be or has been assimilated.

Not containing or combined with nitrogen; (Metallurgy) that has not undergone nitridation. Cf. nitrogenized, adj.

Physical Chemistry. Not rotating the plane of polarization of polarized light. Often (and now usually) qualified by optically.

Producing an alkali: said of metals that form alkalis with oxygen. Cf. alkaligenous, adj.

(un-, prefix1 affix 1.)

Chemistry. Of a substance: that tends to attack and alter the structure of other substances; corrosive.

effected or exerted by minute quantities of metallic ions in solution; acting or being active at very low concentrations.

Having the property of varying its colour.

Of a molecule: whole, not split into oppositely charged ions.

Of, relating to, or of the nature of an osmophore (in either sense).

of, pertaining to, or displaying thermochromism.

Chemistry. Of a chemical system: consisting of a single component.

Containing or representing atoms of the different elements in numbers that do not bear a simple integral ratio to one another or are not in the…

Characterized by the slow release of an active substance (e.g. a drug, a hormone, a plant fertilizer, etc.).

Of, relating to, or caused by sonoluminescence; exhibiting sonoluminescence.

Characterized by one axis of alignment or action.