Daisy Turnbull Brown, 80, a longtime Washington resident and hostess who was active in the NAACP, died Tuesday at Providence Hospital of cardiac arrest.

She was the wife of Dr. Sterling Allen Brown, professor emeritus of English at Howard University and dean of contemporary black poets.

During their 52-year marriage, Mrs. Brown worked as her husband's secretary, typist and research assistant.

She also was hostess, at their Washington home, to a wide circle of friends and former students of Dr. Brown's, including actor Ossie Davis, and his wife, actress Ruby Dee, musicians Duke Ellington and Jellyroll Morton, political activist Stokely Carmichael, Nobel laureate Ralph Bunche, psychologists Kenneth B. Clark and Gunnar Myrdal, whose research was used in the 1954 Supreme Court decision on school desegregation, and Judge William Hastie.

Mrs. Brown served as inspiration for her husband's poetry, which has been described as "black folk verse." Among the poems he wrote for her, was "Long Track Blues": "I went down tothe yards to see the signal lights come on . . . Looked down the tracks where my lovin' babe done gone . . .Lawdy, let your green light shine down on that babe of mine."

Dr. Brown's about-to-be-published "Collected Poems" was dedicated to his wife, whom he called "Rose Ann."

Mrs. Brown was born in Rocky Mount, Va., and graduated from the Virginia Theological Seminary and College.

She was a member of the Howard University Faculty Wives Club and a life member of the NAACP.

Besides her husband, of the home in Washington, survivors include an adopted son, John (Jack) Langston Dennis, also of Washington, and four granddaughters. CAPTION: Picture, DAISY TURNBULL BROWN