熟語JLPT-N4
limited express train (faster than an express train)
特 とっ
とっきゅうlimited express train (faster than an express train)
急 きゅう
きゅうurgentきゅうこうspeedyとっきゅうlimited express train (faster than an express train)きゅうげきsuddenきゅうそくrapid (e.g. progress)きゅうswiftly