The term "athame" is said to be suspected from the Latin term "artavus" which means a kind of quill knife. This knife was described in "The Key of Solomon" as a sickle shaped knife which is in line with the shape of the boline.
This tool is used for magical and ritual purposes only. It is used to direct energy especially when casting a Circle. It can be used for charging and consecrating items as well. The athame, in most traditions, is representative of the element of fire and is one of the 4 elemental tools in witchcraft along with the pentacle, the chalice, and the wand. In the other traditions it is associated with the element of air and the wand represents fire. The athame is also usually the main tool that's representative of a phallus and used in the symbolic version of the Great Rite.
When choosing your athame, take your time. This is a very important tool and to me is the most important tool. Take care of your tools and they will take care of you.