From Latin 'intelligere' (to choose between) — understanding as selecting the significant from the noise.
The ability to acquire and apply knowledge and skills; the collection of information of military or political value.
From Old French 'intelligence,' from Latin 'intelligentia' (understanding, discernment, the power of knowing), from 'intelligere' (to understand, to perceive, to comprehend), from 'inter-' (between, among) + 'legere' (to choose, to pick out, to read, to gather). To understand is, etymologically, to choose between — to pick out the significant from the insignificant, to read meaning from the chaos of sensation. The same 'legere' produced 'lecture,' 'lesson,' 'legend,' 'elect,' and 'collect.' Key roots:
'Intelligence' literally means 'choosing between' — from Latin 'inter' (between) + 'legere' (to choose, to gather). The same 'legere' is in 'elect' (choose out), 'select' (choose apart), 'collect' (gather together), 'neglect' (not choose, not pick up), and 'lecture' (a reading/gathering of words). Every act of intelligence is, at root, an act of selection.