no use: Often incorrectly used for "of no use." Do not say "It's no use to discuss it with you," say, rather, "It is of no use to discuss it."
novice. Compare amateur.
number should not be used with such words as innumerable and numerous, which themselves contain the idea of number (Latin numerus). Say "A countless number," not "an innumerable number."
numerous: Often misused for many. Do not say "numerous cattle were in pasture"; say, rather, "Many cattle were in pasture."
nutty: Used in the sense "lacking in intelligence," this word is a vulgarism to be avoided.
obnoxious: Formerly this word meant "liable, amenable, subject," but the meaning is sometimes forgotten in the more recently acquired sense, "odious, hurtful." This difference is beautifully illustrated by a question propounded to Dean Alford—"Which of these two is right, 'Death is obnoxious to man' or 'Men are obnoxious to death?'" Death, or the idea of death, is certainly distasteful to most men, but, this notwithstanding, all men are subject to death.
observance: Distinguish from observation. Though the act of observing is signified by both, it is, as regards observance, in the sense of holding sacred, whereas, so far as observation is concerned it