Perseverance is defined as: the action or condition or an instance of persevering. Persevere: to persist in a state, enterprise or undertaking in spite of counterinfluences, opposition, or discouragement.

Endurance: the ability to withstand hardship or adversity; esp: the ability to sustain a prolonged stressful effort or activity.

Holding on: to maintain a condition or position: persist, to await something desired or requested. (Merriam-Webster’s Collegiate Dictionary, 10th ed.)