Webster’s Revised Unabridged Dictionary · 1913
Similarity
Sim′i·lar′i·ty, n.; pl. -ties (#). [Cf. F. similarité.] The quality or state of being similar; likeness; resemblance; as, a similarity of features.
Hardly is there a similarity detected between two or three facts, than men hasten to extend it to all. Sir W. Hamilton.