As ever I’m a bit late to the fray on this one having been offline revising the bardic course for the last year or so. While doing that, Nwyfre cropped up and here are my conclusions, mostly from a footnote in bardic booklet 8 which you should have access to either now or shortly:
As Dowgri says, the Welsh word, nwyfre, does mean ‘sky.’ Despite the paucity of evidence in the early literature, much has been made of Nwyfre by Druid revivalists. There is a possibility that Nwyfre is an alternate name for Nudd, meaning ‘cloud.’ An internet search reveals entire websites devoted to him, including one headed “Nwyfre – ‘Noo-if-rey’ Intuitive healing, yoga and celebrancy.” The actual pronunciation is more like NooIV-ruh, the Welsh single ‘f’ being pronounced as ‘v.’ The site’s owners confidently assert that “Nwyfre is the energy that binds all life together, it is the force that we feel coursing through us when we are in nature, or feeling great joy. It is that which connects us all. Nwyfre has many other names in other cultures: prana, chi, spirit to name just three.” Another website likens it to ‘The Force’ in Star Wars! This interpretation originated with our old friend, the renowned 18th century bard and forger of medieval manuscripts, Iolo Morgannwg. In a posthumous collection of his writings, Iolo refers to “nwyvre, which is God, from Whom proceeds every life, strength, and intellect, and every perception and sense” (J. Williams ap Ithel (ed.), Barddas: A Collection of Original Documents Illustrative of the Theology, Wisdom and Usages of the Bardo-Druidic System of the Isle of Britain, 1862, page 373). Iolo’s interpretation was taken up by the Ancient Druid Order, from which it was inherited by their offshoot, the Order of Bards, Ovates and Druids, who popularised the ‘prana’ interpretation via their courses.
In talks with Philip Carr-Gomm, I’ve said that OBOD seems to use nwyfre to mean the sort of creative energy that I see as being part and parcel of what awen is. In terms of energies that course within the body, we tend to to use the Welsh anadl, which means ‘breath,’ from a root with the combined meaning of ‘breath’ and ‘soul.’