(to cause something) to become course

corrupt

to make (something) dirty, impure or diseased (by touching or adding something impure)

adulterate

to make (a person, currency etc) lower in value, poorer in quality etc

degrade, shame

to cause (a person) to be less moral or less deserving of respect

shame, humiliate

to become of less value or worse (in quality)

decay, degenerate

to make (air, rivers etc) dirty, impure

make dirty; corrupt

to destroy (a government, religion etc) by weakening people's trust, confidence, belief

rebel, destroy

a twisted or bent condition in a piece of wood etc caused by shrinking or expansion; (to cause something) to become bent or twisted from the usual or natural shape

bend, distort

bent or twisted

bend, distort