Other forms: signposts; signposted; signposting
A signpost is a raised marker on the side of a road that provides some kind of information — like how many miles you have to travel to a landmark (like the golden arches of McDonald's).
A signpost can mark a historical site, a business, or the distance to a city. Smaller roads that meet at an intersection or crossroads often have a signpost marked with arrows and town names, making it clear which direction you should go. Sometimes signpost is used figuratively, to mean an indicator or hint: "The mayor's vote to fund a new school acted as a signpost to her feelings about education in general."