eagle-eyed

the compound adjective 'eagle-eyed' is a metaphorical formation in english, drawing directly from the perceived characteristic of the eagle. the word 'eagle' entered english from the old french 'aigle', which itself descended from the latin 'aquila'. the second element, 'eyed', is derived from the old english noun for 'eye', combined with the adjectival suffix '-ed' to indicate possession of a quality. the logic of the word is transparently figurative: it compares a person's visual acuity or sharp observational skills to the legendary keen sight of an eagle, a bird famed in folklore and natural history for its ability to spot distant prey. this combination creates a vivid and enduring metaphor for exceptional perceptiveness.

Structure: eagle + eyed eagle: from latin 'aquila', via old french 'aigle', meaning the bird of prey known for its keen vision. eyed: from old english 'ēage' (eye) + the suffix '-ed', meaning 'having eyes (of a specified kind)'.