Crossword puzzle clue "telescopic sighting aid"

a fine wire at the focus of an optical instrument, crossing the field of view, to aid in positioning or measuring, also CROSSWIRE

the lens nearest the eye in an optical instrument

a piece of transparent matter with one or both surfaces curved to cause regular convergence or divergence of rays passing through it

pertaining to the lore, the side of a bird's head, also LORAL

to equip, fit out

to direct a course