all of a dither Antonyms

centered self-assured self-contained self-possessed stolid together unmoved unruffled unshakable unshaken undisturbed unagitated laid-back happy-go-lucky coolheaded untroubled unflustered unperturbed sedate reposeful chilled controlled cool-headed disciplined even harmonious level limpid mellow nerveless nonplussed pacific peaceable phlegmatic poised possessed relieved well-adjusted