Where does “diftongo” come from?

diftongo (Ido) comes from Esperanto diftongo, from English diphthong, from French diphtongue, from Latin diphthongus, from Ancient Greek δῐ́φθογγος.

diftongo (Ido): diphthong

Definitions

Step	Language	Word	Meaning
1	Esperanto	diftongo	diphthong
2	English	diphthong	A complex vowel sound that begins with the sound...
3	French	diphtongue	diphthong; digraph, trigraph; first-person...
4	Latin	diphthongus	diphthong
5	Ancient Greek	δῐ́φθογγος	—

diftongo — Etymology, Origin & Word History | Etymology Explorer