This is part of a lecture by the late Murata Naoki, who was an 8th dan in Jūdō, an author (who wrote many books on Jūdō) and curator of the Kōdōkan Jūdō Museum.

He mentions that the full name that Kano Jigoro (嘉納治五郎) gave to his art was 'Nihon-den Kōdōkan Jūdō' (日本伝 講道館 柔道 - Japanese tradition place for learning the way pliant way) to give respect to the Jūjutsu (柔術) traditions, while still expressing his innovative approach.

The name Jūdō' (柔道) was first used by Jikishin-ryū (直心流 - a derivative of Ryōi Shintō-ryū 良移心当流) in 1673. It is believed Kano knew this and was inspired to use the same term to describe his new approach.

Sadly, Murata Sensei passed away on 9th Aril this year (2020).

Reference: https://youtu.be/jG9mSJrowQE?t=5331