means The wax structure of six-sided cells that bees build to store honey, pollen, and their young — or, by extension, anything riddled with a similar pattern of small openings.

from A plain Old English compound: hunig ('honey') plus camb ('comb'). The 'comb' here isn't the hair tool — both senses descend from the same root meaning something toothed or ridged, and the rows of waxen cells reminded early English speakers of a comb's teeth. The hexagonal sense bleeds into the verb 'to honeycomb,' meaning to bore through with cavities — caves, old timbers, and corroded metal all get described as honeycombed.