- Rōmaji transcription of
From Old Spanish fondo, from Latin fundus, ultimately from Proto-Indo-European *bʰudʰmḗn, with the Latin noun taking on an adjectival sense in Spanish. An alternative theory sees the Old Spanish fondo as a shortening of an earlier, pre-literary *perfondo, from the Latin adjective profundus instead, which matches with the sense of the word better; however this is uncertain. The word profundo is a neologism later borrowed from Latin. Cf. also the Spanish noun fondo (“bottom”), which may have preserved the old initial 'f' to distinguish it from the adjective hondo, its doublet.
- “hondo” in Diccionario de la lengua española, Vigésima tercera edición, Real Academia Española, 2014.