The answer to the crossword for the term PART OF A EURO is AXON. An axon is a long, thin projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body. Axons are essential for the functioning of the nervous system, as they transmit signals from one neuron to another. In the context of the euro, an axon could refer to the economic and financial connections between countries in the European Union.