Friendship is not institutionalized in American society; hence, perceptions of it vary. Rather than studying sources of this variation, most scholars ignore the complexity, bemoan the difficulty it causes in analysis, or eliminate it. We examined the frequency of use of previously studied and emergent characteristics of friendship as definitional criteria and the age, gender, and cultural patterns associated with them. Data are from two North American cities: the Andrus Study of Older Adult Friendships in southeastern United Stares (28 women and 25 men, age 55 to 84), and the Social Relations Project in western Canada (39 women and 25 men, age 55 to 87). Definitions of friendship differed across age and gender groups within each culture, but most striking is cross-cultural variation.