soften

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

• intransitive verb To make soft or softer.
• intransitive verb To undermine or reduce the strength, morale, or resistance of.
• intransitive verb To make less harsh, strident, or critical.
• intransitive verb To become soft or softer.

from The Century Dictionary.

• To remove from (natural water) the hardness due to the presence of salts of calcium or magnesium in solution. In the case of temporary hardness, boiling the water or adding to it a carefully determined proportion of calcium hydroxid is used to produce softening; in the case of permanent hardness, sodium carbonate, not in too large excess, may be added. See hardness, 2.
• To become soft or less hard.
• To become less rude, harsh, severe, or cruel; grow less obstinate or obdurate; become more susceptible of humane feelings and tenderness; relent.
• To pass by soft, imperceptible degrees; melt; blend.
• To make soft, or more soft.
• To mollify; make less fierce or intractable; make more susceptible of humane or fine feelings: as, to soften a hard heart; to soften savage natures.
• To make tender; make effeminate; enervate: as, troops softened by luxury.
• To make less harsh or severe, less rude, less offensive or violent; mitigate: as, to soften an expression.
• To make less glaring; tone down; make less sharp or harsh: as, to soften the coloring of a picture; to soften the outline of something.
• To make less strong or intense in sound; make less loud; make smooth to the ear: as, to soften the voice.

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

• transitive verb To make soft or more soft.
• transitive verb To render less hard; -- said of matter.
• transitive verb To mollify; to make less fierce or intractable.
• transitive verb To palliate; to represent as less enormous.
• transitive verb To compose; to mitigate; to assuage.
• transitive verb To make less harsh, less rude, less offensive, or less violent, or to render of an opposite quality.
• transitive verb To make less glaring; to tone down.
• transitive verb To make tender; to make effeminate; to enervate.
• transitive verb To make less harsh or grating, or of a quality the opposite.
• intransitive verb To become soft or softened, or less rude, harsh, severe, or obdurate.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb transitive To make something soft or softer.
• verb transitive To undermine the morale of someone (often soften up).
• verb transitive To make less harsh
• verb intransitive To become soft or softer

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb make less severe or harsh
• verb become soft or softer
• verb lessen in force or effect
• verb make (images or sounds) soft or softer
• verb make soft or softer
• verb protect from impact
• verb give in, as to influence or pressure