means A cautious, watchful state of mind in which you're alert to possible danger, deception, or trouble.

from From 'wary' plus the noun-making suffix '-ness.' 'Wary' descends from Old English 'wær' meaning 'watchful, careful, prudent,' a cousin of Old Norse 'varr' (attentive) and related to the Germanic root that also gives us 'aware' and 'beware.' The deep ancestor is a Proto-Indo-European root meaning 'to perceive, watch out for' — the same family that surfaces in Latin 'verērī' (to revere, to fear) and 'guard.' At heart it's an old word for keeping your eyes open.