guide

n. & v.
—n.
1 a person who leads or shows the way, or directs the movements of a person or group.
2 a person who conducts travellers on tours etc.
3 a professional mountain-climber in charge of a group.
4 an adviser.
5 a directing principle or standard (one's feelings are a bad guide).
6 a book with essential information on a subject, esp. = GUIDEBOOK.
7 a thing marking a position or guiding the eye.
8 a soldier, vehicle, or ship whose position determines the movements of others.
9 Mech. a a bar, rod, etc., directing the motion of something. b a gauge etc. controlling a tool.
10 (Guide) Brit. a member of a girls' organization similar to the Scouts.
—v.tr.
1 a act as guide to; lead or direct. b arrange the course of (events).
2 be the principle, motive, or ground of (an action, judgement, etc.).
3 direct the affairs of (a State etc.).
Phrases and idioms:
guided missile a missile directed to its target by remote control or by equipment within itself. guide-dog a dog trained to guide a blind person. guide-rope a rope guiding the movement of a crane, airship, etc. Queen's (or King's) Guide a Guide (sense 10) who has reached the highest rank of proficiency.
Derivatives:
guidable adj. guider n.
Etymology: ME f. OF guide (n.), guider (v.), earlier guier ult. f. Gmc, rel. to WIT(2)