The ability to think clearly and make good decisions. A depth of perception especially in practical matters.
1) Her political acumen won her the election.
2) His lack of business acumen is worrisome.
Latin acuere which means 'point'.
astuteness, cunningness, shrewdness, intelligence, caginess/cageyness,clear-sightedness, canniness, foxiness, hardheadedness, sharpness, wit
obtuse, unknowing, guileless, ingenuous, undesigning