In Japan,
Chibi means dwarf or tiny.
Chibi-kyara (chibi character) just means small/tiny character.
Deformed means certain parts of body exaggerated by being drawn large, most and almost all of the time, the head. Height of the character is abstract in this matter.
Super-Deformed comes from SD Gundam and should look like the Gundams in that show. SD characters are usually two heads height in proportion.
For SD characters, they can be at a normal height or smaller than normal height but for Chibi characters, they are always small (from another creature's point of view)
Chibi-kyara and SD are sometimes interchangeable. Just that Chibi is a more general word while SD is a more "otaku" word.
Definitions could be different in English speaking worlds, just like how hentai means weirdo/pervert in Japan but erotic art in everywhere else.