sagacity, sagaciousness, judgment, judgement, discernment

ability to make good judgments

• eye — good discernment (either with the eyes or as if with the eyes)
• common sense, good sense, gumption, horse sense, sense, mother wit — sound practical judgment
• judiciousness — good judgment
• discretion, discreetness, circumspection, prudence — knowing how to avoid embarrassment or distress
• injudiciousness, indiscreetness — lacking good judgment

• wisdom, sapience — ability to apply knowledge or experience or understanding or common sense and insight