Japanese Noun ひやく • (hiyaku) 飛躍: leaping 秘薬: secret medicine Verb ひやくする • (hiyaku suru) suru (stem ひやくし (hiyaku shi), past ひやくした (hiyaku shita)) 飛躍: to make a leap forwardWikiwand - on Seamless Wikipedia browsing. On steroids.