multimillionaire Someone with money or assets worth several millions in value. Related 'metric' families: yotta; zetta; exa; peta; tera; giga; mega; kilo; hecto; deka; deci; centi; micro; nano; pico; femto; atto; zepto; yocto. Found on http://www.wordinfo.info/words/index/info/view_unit/1312/3