They are synonyms, because they are different words for the same thing.
guts or intestines
entrails
Entrails are essentially the guts of a person, animal, etc. Therefore, fish entrails would be, by definition, the fish's insides.
They can be antonyms (opposite meanings), not synonyms.
go on www.synonym.com 4 synonyms & antonyms
there is no synonyms or antonyms for convection current
Synonyms: moving Antonyms: Fixed, Stationary
Antonyms: opposite. Synonyms: similar.
Synonyms. Synonyms are words the same in meaning and antonyms are opposites
they are closer to synonyms than antonyms, although they are not direct synonyms.
They are synonyms. Synonyms have similar meanings, antonyms have opposing meanings.
Antonyms. Antonyms = Opposites Synonyms = Same Meaning