a sneer
Examples
A new idea is delicate. It can be killed by a sneer or a yawn; it can be stabbed to death by a quip and worried to death by a frown on the right man's brow.
My novels are what is known as popular and sell very well, but I am not a critic's favourite, indeed I am generally dismissed with a sneer as a bestseller and not reviewed at all.
Being right is not too difficult. Your choose your perception. You select your information. You leave out what does not suit you. You drag in some general-purpose value words. You throw in a sneer or two about the opposition, and you are a fine fellow who made a fine speech.
A sneer is the weapon of the weak.