guide

n. 1 person who leads or shows the way. 2 person who conducts tours. 3 adviser. 4 directing principle. 5 book with essential information on a subject, esp. = *guidebook. 6 thing marking a position or guiding the eye. 7 bar etc. Directing the motion of something. 8 (guide) member of a girls' organization similar to the scouts. v. (-ding) 1 act as guide to. 2 be the principle or motive of. [french from germanic]

n. The leather strap by which the shield of a knight was slung across the shoulder, or across the neck and shoulder.