Eburacon is the old Celtic name for
York. Eboracum is the Latinised form. The name almost certainly refers to yew trees.
England (and therefore
York) was inhabited first by the Celts, who named
York Eburacon, for the yew tree(s) there (probably a sacred grove of some sort). The Romans came, and spelt the name in Latin as Eboracum. After the Romans left, the Angles, Saxons and Danes (Germanic tribes) came. Not speaking much Latin, they reinterpreted the name Eboracum as Eoforwic - boar farm.
Does that help?