sense
One of the meanings of a word. Dictionary entries number the senses.
etymology
The history of a word: where it came from and how its meaning changed.
contronym
A word that can mean two opposite things, like dust (remove dust, or sprinkle with powder).
connotation
The feeling or idea a word suggests, beyond its dictionary meaning.
loaded word
A word chosen to stir up strong positive or negative feelings.
euphemism
A gentler or vaguer word used in place of one that seems harsh, like passed away for died.