If you want more, check in a thesaurus (there are some online ones) and usually along with synonyms, they have antonyms.
Antonyms for "artificial" are genuine, real, and natural.
synonyms: spontaneous, unaffected, genuine, unmannered antonyms: unnatural, supernatural
antonyms for said
Calabash has no antonyms.
antonyms of mutered
Some antonyms for adversarial:AccordanceAgreeableAmicableBeneficialConcordanceConcordConstructiveEquableFavorableHarmoniousHelpfulPeacefulPlacidPlacidlyPromisingServiceableSupportableTranquilTruceUsefulValuable
antonyms for slender
constellations antonyms
Some Antonyms for the word interpret are misinterpret and misunderstand.
Some antonyms for heartily include: gravely, indifferently.
Some antonyms for the verb reside are depart, move, leave, or vacate.
There are no antonyms of syntax. It's a noun.