Definition of "taskmistress"

Not only under the laſh of my taſk-miſtreſs, but the drudge of the maid, apprentices and children, I never had a taſte of human kindneſs to ſoften the rigour of perpetual labour.

1798, Mary Wollstonecraft Godwin, “[Maria: or, The] Wrongs of Woman”, in W[illiam] Godwin, editor, Posthumous Works of the Author of A Vindication of the Rights of Woman. […], volume I, London: […] J[oseph] Johnson, […]; and G[eorge,] G[eorge] and J[ohn] Robinson, […], chapter V, page 87