If your parents brought you up vigilantly, chances are that you were admonished to use your words carefully. As far as writing is concerned, that instruction is one of the most valuable lessons you learned.
Consider the power of connotation, the sense of a word apart from its denotation, or literal meaning. Unless you have your heart set on being a propagandist, be cautious about the synonym you choose in a particular context.
Look, for example, at thin and its associated words: Thin, itself, is an ambiguous term; depending on context, it might connote an healthful or unhealthful appearance. To say that one is lithe, slim, slender, svelte, or willowy, meanwhile, connotes an attractive body type maintained, perhaps, by engaging in physical fitness and/or eating sensibly.
However, anorexic, bony, and skinny suggest an excessive thinness. To say, for example, that a fashion model is lithe is complimentary; to describe her as bony is pejorative. (An anonymous wag went further in coining the phrase “bag of antlers” to suggest a woman whose bones protrude in such an unsightly fashion that she resembles such an object.)
Loaded language can have much more loaded consequences. A famous — or infamous — example is the popularity during the mid-1980s of the term “freedom fighters,” which Ronald Reagan, then president of the United States, used to characterize counterrevolutionaries fighting the Sandinista government of Nicaragua.
Some people observed at the time that the actions of some of these guerrillas, who were being supported by the US government, merited instead the term terrorists and that the Reagan administration was cynically using a term meant to disingenuously associate the counterrevolutionaries (often called contras, from an abbreviation of the Spanish form of that word) with the patriots of the Revolutionary War. The contra controversy was exacerbated by the fact that the Sandinistas themselves behaved at times like terrorists, but this complication didn’t negate the propagandistic taint of “freedom fighters.”
Similar words with negative connotations include militant, which describes someone who may not necessarily engage in combat or even physical violence but is an ardent and perhaps destructive protester, and vigilante; the latter word connotes someone who flouts the rule of law in seeking to uphold it and suggests a dangerous disregard for justice in the course of retribution for unproven crimes.
Political propaganda characterizes a given geopolitical entity by a weighted word depending on the writer’s perception of the nature of the political system that entity operates under: Government is a neutral or positive term; regime or junta, by contrast, connotes a dictatorship.
Similarly, an academic or a scholar is someone employed in a professorial capacity whose opinions you agree with; if you’re at odds with such a person’s viewpoint, you might label him or her an elitist or refer to the person as someone isolated from reality in an ivory tower. A government employee whose work you support is a public servant; one who has an adverse impact on your quality of life is a bureaucrat. Politicians whose bills propose expenditures you desire are investing in the nation’s infrastructure; those whose legislation you consider wasteful are spending your hard-earned tax dollars.
And, perhaps most provocative, people who support the right of women to have an abortion call themselves pro-choice, while their opponents label them pro-abortion. On the other hand, what one person might call an antiabortionist would likely self-identify as pro-life.
This post does not advocate avoidance of loaded language; if you wish to express your opinion, you will likely make use of weighted words. But if your intention is to express impartiality, take care in the terms of art you choose.