Answer:
Synonyms for invisible
discreet, inconspicuous, unnoticeable, unobtrusive
Synonyms for royalty
augustness, kingliness, majesty, stateliness
Synonyms for unthinkable
fantastic (also fantastical), implausible, inconceivable, incredible, incredulous, unbelievable, uncompelling, unconceivable, unconvincing, unimaginable
Synonyms for plague
afflict, agonize, anguish, bedevil, beset, besiege, curse, excruciate, harrow, persecute, rack, torment, torture
hope it helps
