ふくらす Also written 膨らす, 脹らす Meanings Godan verb, Transitive to expand; to inflate See also: 膨らます (ふくらます). Example sentences トムは水風船をパンパンに膨らせた。Tom filled the water balloon. Related forms 膨れる (ふくれる) to swell (out) (intransitive partner) Jinuma: Japanese Dictionary · Word lists