temper

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To modify by the addition of a moderating element; moderate: synonym: moderate.
• intransitive verb To bring to a desired consistency, texture, hardness, or other physical condition by blending, admixing, or kneading.
• intransitive verb To harden or strengthen (metal or glass) by application of heat or by heating and cooling.
• intransitive verb To strengthen through experience or hardship; toughen.
• intransitive verb Music To adjust (the pitch of an instrument) to a temperament.
• intransitive verb To be or become tempered.
• noun A state of mind or emotion; disposition.
• noun Calmness of mind or emotions; composure.
• noun A tendency to become easily angry or irritable.
• noun Anger; rage.
• noun A characteristic general quality; tone.
• noun The condition of being tempered.
• noun The degree of hardness and elasticity of a metal, chiefly steel, achieved by tempering.
• noun A modifying substance or agent added to something else.
• noun Archaic A middle course between extremes; a mean.

from The Century Dictionary.

• noun A metal or alloy added to another to produce certain physical properties; specifically, an alloy of one part of copper and two of tin to be added to pure tin to produce a fine grade of pewter; an alloy containing arsenic with lead sometimes added to the molten metal to give hardness to shot.
• In leather-manufacturing, to apply to (hides) a process in which the hides, after they are practically finished, are dampened, covered in piles, and allowed to stand and season, the drier hides absorbing moisture from the damper ones, and vice versa.
• noun Mixture or combination of different ingredients or qualities, especially in the way and the proportions best suited for some specific purpose: as, the temper of mortar.
• noun Constitution; consistency; form; definite state or condition.
• noun Temperament.
• noun Disposition of mind; frame of mind; inclination; humor; mood: as, a calm temper; a hasty temper; a sullen or a fretful temper.
• noun Calmness of mind; temperateness; moderation; self-restraint; tranquillity; good temper.
• noun Heat of mind or passion; irritation; disposition to give way to anger, resentment, or the like: as, he showed a great deal of temper.
• noun Middle character or course; mean or medium; compromise.
• noun The state of a metal, particularly as to its hardness and elasticity: as, the temper of iron or steel.
• noun In sugar-works, white lime or other alkaline substance stirred into a clarifier filled with cane-juice, to neutralize the excess of acid.
• To modify by mixing; mix; blend; combine; compound.
• To combine in due proportions; constitute; adjust; fit.
• To moisten, mix, and work up into proper consistency; prepare by moistening, mixing, or kneading.
• To modify or qualify by blending: as, to temper indignation with pity.
• Hence To restrain; moderate; mitigate; soften; tone down the violence, severity, or harshness of; mollify; soothe; calm.
• In music, to tune or adjust the pitch of (the tones of an instrument of fixed intonation, like an organ or pianoforte), with reference to a selected principle of tuning.
• To attune.
• To govern; control; regulate; train.
• To bring to a proper degree of hardness and elasticity for use, as steel or other metal.
• To dispose.
• To accord; keep agreement.
• To become soft and plastic; be molded; acquire a desired quality or state.

from the GNU version of the Collaborative International Dictionary of English.

• transitive verb To mingle in due proportion; to prepare by combining; to modify, as by adding some new element; to qualify, as by an ingredient; hence, to soften; to mollify; to assuage; to soothe; to calm.
• transitive verb To fit together; to adjust; to accomodate.
• transitive verb (Metal.) To bring to a proper degree of hardness.
• transitive verb A Latinism & Obs. To govern; to manage.
• transitive verb To moisten to a proper consistency and stir thoroughly, as clay for making brick, loam for molding, etc.
• transitive verb (Mus.) To adjust, as the mathematical scale to the actual scale, or to that in actual use.
• noun The state of any compound substance which results from the mixture of various ingredients; due mixture of different qualities; just combination.
• noun Constitution of body; temperament; in old writers, the mixture or relative proportion of the four humors, blood, choler, phlegm, and melancholy.
• noun Disposition of mind; the constitution of the mind, particularly with regard to the passions and affections
• noun Calmness of mind; moderation; equanimity; composure.