Synonyms for Hesitation (same or very similar meaning)
WordNet sense 1 (indecision in speech or action):
vacillation, waveringWordNet sense 2 (a certain degree of unwillingness):
disinclination, hesitancy, indisposition, reluctanceWordNet sense 3 (the act of pausing uncertainly):
falter, faltering, waverFrom the ODE community, based on WordNetadd/edit