Style Guide beginning with O

Oxymoron

Oblivious

If you are oblivious of something, you are not simply unaware of it. You have forgotten it or are absent-mindedly unaware of it.
One

Try to avoid one as a personal pronoun. You will often do instead.
Only

Put only as close as you can to the words it qualifies. Thus, These animals mate only in June. To say They only mate in June implies that in June they do nothing else.
Onto

On and to should be run together when they are closely linked as in He pranced onto the stage. If, however, the sense of the sentence makes the on closer to the preceding word, or the to closer to the succeeding word, than they are to each other, keep them separate: He pranced on to the next town or He pranced on to wild applause.
Overused words

Nothing betrays the lazy writer faster than fly-blown phrases used in the belief that they are snappy, trendy or cool. Some of these clichés are deliberately chosen (bridges too far; empires striking back; kinder, gentler; f-words; flavours of the month; Generation x; hearts and minds; $64,000 questions; southern discomfort; back to the future; shaken, not stirred; thirty-somethings; windows of opportunity; where's the beef?), usually from a film or television, or perhaps a politician. Others come into use less wittingly, often from social scientists. If you find yourself using any of the following vogue words, you should stop and ask yourself whether (a) it is the best word for the job (b) you would have used it in the same context five or ten years ago, and if not why not:

Read more
Overwhelm

Overwhelm means submerge utterly, crush, bring to sudden ruin. Majority votes, for example, seldom do any of these things. As for the ethnic Albanians in Kosovo, although 90% of the population, they turned out to be an overwhelmed majority, not an overwhelming one, until NATO stepped in.
Oxymoron

An oxymoron is not an unintentional contradiction in terms but a figure of speech in which contradictory terms are deliberately combined, as in bitter-sweet, cruel kindness, friendly fire, joli laid, open secret, sweet sorrow, etc.