Prior to this, "calaf" was written "galaf" with an initial èg not èc. As a matter of fact ancient Brythonic /Welsh "*galaf" as a term, existed in the far, far remote past. It existed before the time when Hen Gymraeg (Old Welsh) developed from the Brythonic language .
The form "galaf" is simply the lenited form of calaf cf. Cornish kala, Bret. kolo.
To be precise, "galaf", was around prior to Roman legions setting their eyes on any Celtic iron age settlements in Wales. Actually, the age of "galaf" goes back in time when the British isle was archeologically labeled: Britain of late pre-Roman Iron Age.
Then, "galaf" was frequently found in compounds such as " Cangaleifon", and "Gwyngalaf" (gwyn = white + galaf = stalks).
The second elements of regular compound nouns lenites, hence /k/ >/g/.
These were in reference to the old names of the Druidic months of August and September. These were in allusion to the whitened appearance of stalks (Cf. Gwyngalaf, another old name for the same months.) and were often mentioned in 'The Wood Memorials of the Bards'- see "The Barddas of Iolo Morganwg"; a Collection of Original Documents, illustrative of the Theology, Wisdom, and Usages of the Bardo-Druidic System of the Isle of Britain. i.412, 416.
Iolo invented most of his material. It does not, very often, represent any older traditions or learning.
You are more than welcome to view the scanned definition from the Welsh dictionary (fig. #4 at the bottom of the web page) by clicking the following URL :
The whole point of this investigation is quite simple. It gives a surety of authenticity to the existence of "*galaf" as a native Welsh term, centuries before any Roman invasion. Based on this fact, I would say to Guto: Any idea of the existence of a " Clt *calam" is definitely out of question.
There is no Welsh word <galaf> and such a form has never existed. My question is more about the vowels.