Edda means sage

Both the name of the elder womman Edda and the name of the Edda book match the Sanskrit’s addha (clearly) and addhAti (sage)

अद्धाति m. addhAti sage

Sanskrit dictionary

[«previous (A) next»] — Addha in Sanskrit glossary

Source: DDSA: The practical Sanskrit-English dictionary

Addhā (अद्धा).—ind. [atyate at taṃ santataṃ gamanaṃ jñānaṃ vā dadhāti kvip Tv.]

۱) Truly, clearly, surely, undoubtedly, in truth, really, certainly, indeed; को अद्धा वेद (ko addhā veda) Ṛgveda 1.129.6. अद्धा श्रियं पालितसङ्गराय प्रत्यर्पयिष्यति (addhā śriyaṃ pālitasaṅgarāya pratyarpayiṣyati) R.13.65.