541. Catastrophe : Calamity
542. Gather : Congregate
543. Logical : Rational
544. Latent : Hidden
545. Repeal : Cancellation
546. Ameliorate : Improve
547. Petition : Appeal
548. Parsimony : Miserliness
549. Dissuade : Discourage
550. Valiant : Courageous
551. Transient : Transitory
552. Podium : Dais
553. Meagre : Inadequate
554. Genuine : Authentic
555. Visceral : Bodily
556. Deter : Hinder
557. Felicitated : Congratulated
558. Disease : Illness
559. Frugal : Economical
560. Humane : Sympathetic
561. Ecstasy : Joy
562. Spurious : Fake
563. Forsaken : Abandoned
564. Invoice : Statement
565. Temerity : Audacity
566. Wily : Cunning
567. Impetuous : Hasty
568. Revenue : Income
569. Assault : Attack
570. Solicit : Request
571. Toil : Work Hard
572. Mundane : Ordinary
573. Accomplish : Achieve
574. Snooze : Sleep
575. Hallucination : Delusion
576. Curious : Inquisitive
577. Merge : Blend
578. Vivacious : Lively
579. Enterprising : Finding out new ways of doing things
580. Mastery : Authority
581. Adequate : Enough
582. Relish : Enjoy
583. Invincible : Unassailable
584. Advocate : Support
585. Insipid : Bland
586. Impeccable : Flawless
587. Eternal : Forever
588. Peruse : Examine
589. Voracious : Greedy
590. Bliss : Happiness
591. Conceal : Hide
592. Hard : Difficult
593. Peril : Danger
594. Brisk : Quick
595. Prognosis : Forecast
596. Dwindle : Decrease
597. Gourmet : Gastronome
598. Onus : Responsibility
599. Flung : Threw
600. Greet : Welcome