Using Lexipedia you can visually map out words and concepts in a clean and friendly interface. No more thumbing through a dictionary, or fumbling through a single-word search; with Lexipedia you can see related words, synonyms, antonyms and fuzzynyms. And best of all, it's absolutely free!
adj.
impossible or nearly impossible to see; imperceptible by the eye; "the invisible man"; "invisible rays"; "an invisible hinge"; "invisible mending"
adj.
impossible or difficult to perceive by the mind or senses; "an imperceptible drop in temperature"; "an imperceptible nod"; "color is unperceivable to the touch"
adj.
obvious to the eye or mind; "a tower conspicuous at a great distance"; "wore conspicuous neckties"; "made herself conspicuous by her exhibitionistic preening"
adj.
capable of being seen; or open to easy view; "a visible object"; "visible stars"; "mountains visible in the distance"; "a visible change of expression"; "visible files"