In Irish we have a word "colm" which means pigeon, dove. Official etymology of this word is that it comes from Middle Irish "colum", from Old Irish "columb", from Latin "columbus", from Ancient Greek "κόλυμβος" kolumbos.
In Serbian we have a word golub which means pigeon. Official etymology of this word is that it comes form proto Slavic golǫbь, of unknown origin. Possibly related to Latin columba, columbus.
I would like here to propose an alternative etymology for these two words from Irish and Serbian language.