inconsideration

Etymology
and its source,.

Noun

 * 1) Lack of due consideration; inattention to consequences, thoughtlessness.
 * , II.11:
 * new trained Souldiers, and such as are but novices in the trade, doe often headlong, and hand over head cast themselves into dangers, with more inconsideration, than afterward when they have seene and endured the first shocke, and are better trained in the schoole of perils.