United States tennis player who in 1938 was the first to win the Australian and French and English and United States singles championship in the same year (1915-2000)
the psychological feature that arouses an organism to action toward a desired goal; the reason for the action; that which gives purpose and direction to behavior; "we did not understand his motivation"; "he acted with the best of motives"
the act of motivating; providing incentive
the condition of being motivated; "his motivation was at a high level"