The answer would be synonym. A synonym is a word that means almost the same thing as another. When you pamper a pet you give them a lot of attention, or spoil them.
The verbs pamper and spoil are different words that possess the same meaning. They both refer to the action of being too indulgent or lenient to a kid, giving them too much attention and even too many material things and, by doing so, harming their character. If the two words have the same meaning, they are synonyms.
They are not antonyms, since this type of words are the ones the have opposite meanings. They are not mereley analogous. Analogous words present some sort of connection between them, but they don't have the same meaning (for example, brain and computer). Finally, they are not homophones. Homophones are words that present the same pronunciation, but different spellings and meanings.
