A gerund is a form in which a verb functions like a noun.
'Hashiru koto' is an example of a Japanese gerund.
分詞 (participle) is a verb form used as an adjective, whereas 動名詞 functions as a noun.
Compound of 動 (dō, 'action, motion') + 名詞 (meishi, 'noun'), literally 'action noun'. A calque from Western grammatical terminology.