Existing, living, conscious...
NOTE: you can find synonyms and antonyms on thesaurus.com
There are many examples of different words that mean the same thing. Some examples of different words that mean the same thing are warm and hot and cold and freezing.
The term for words from different languages that look similar and mean the same thing is "cognates."
The two words mean the same thing.
other than, variant, divergent, dissimilar
DaringLoyal Brave Not afraid to do anything
The term for words that are different but mean the same thing is called a synonym. You will find synonyms in a thesaurus and quite possibly an updated dictionary.
A synonym for "Clue" could be "hint". Synonyms are two words that are different words, but mean the same thing.
Shabby and different do not mean the same thing.
Synonyms are the different words that mean the same thing. Like for the word mean, a synonym would be unkind. Antonyms are words that mean the opposite of a word. For the word mean, an antonym might be nice.
The general term for different words that mean the same thing is "synonyms". When the words also sound alike (as with the archaic "quire" and modern "choir"), they are considered variant spellings of the same word.
I would think that things that mean the same as unique are the following: different, unusual, rare, one, uncommon.
One example of words that have the same spelling but different meanings and pronunciations is "tear." It can mean a drop of moisture or to rip something apart, and its pronunciation changes depending on the meaning.