Hesitancy, n.
Etymology: [L. haesitantia a stammering.]
1. The act of hesitating, or pausing to consider; slowness in deciding; vacillation; also, the manner of one who hesitates.
2. A stammering; a faltering in speech.
Shades of meaning
Fernald has no entry of its own for hesitancy; he lists it under doubt.
He lists it without comment; the entries above explain its neighbors.