(a.) Capable of existing in harmony; congruous; suitable; not repugnant; -- usually followed by with.

accordant affable affirmative agreeable agreeing akin amiable amicable answerable appropriate at one attuned blissful cheerful civil clubbable clubbish clubby coexistent coexisting coherent coincident coinciding commensurate communicative companionable companionate complaisant concordant concurring conformable congenial congruent congruous consentaneous consentient consistent consonant cooperating cooperative cordial correspondent corresponding courteous desirable dulcet empathetic empathic en rapport enjoyable equivalent fair fair and pleasant felicific felicitous fine fit fit for society fitting fond of society frictionless friendly genial good goodly gracious grateful gratifying gregarious harmonious heart-warming honeyed hospitable in accord in agreement in concert in rapport in sync in synchronization in tune inaccordance inharmony likable like-minded meet mellifluous mellow nice of a piece of like mind of one mind on all fours peaceful pleasant pleasing pleasurable pleasure-giving pleasureful positive proper proportionate reconcilable rewarding satisfying self-consistent sociable social social-minded suitable sweet symbiotic sympathetic synchronized synchronous together unanimous understanding uniform unisonant unisonous united urbane welcome