Synonym is :
a word that means the same, or almost the same, as another word in the same
language, either in all of its uses or in a specific context.
Examples of synonyms in this sense are "environment" and "surroundings" and
the verbs "tear" and "rip."
word with opposite meaning: a word that means the opposite of another
word. For example, "hot" is the antonym of "cold."