Dear Word Detective: So, I've heard this phrase used many times. The problem is I'm not sure if it's "guy wire" or "guide wire," though I'm tending toward the former as that's what I've seen in print. What's its origin and meaning? -- Jenny
I'm fairly certain that the phrase you mean is "guy wire," although there are such things as "guide wires" used in various medical procedures, including catheterization (whee!). But if you're thinking about the long wires or cables that keep tall antennas and the like from falling over, we're definitely talking "guy wires." However, because "guy" is only used in this fairly limited sense, it is entirely possible that eventually everyone will call such tethers "guide wires" and "guy wires" will fade away.
There are actually two entirely separate words "guy" in English. The "guy" of "guy wire" comes from the Old French "guie." Ironically, given the confusion with "guide," the same root is also related to our modern word "guide." Even more ironically, the original meaning of "guy" when it first appeared in English in the 14th century was "a guide, a leader." That sense is long obsolete, but our modern kind of "guy" developed aboard ship, where "guy lines," chains or ropes were used to steady cargo that was being hoisted to and from the ship. Stationary "guys" also supported and stabilized anything, such as the ship's masts or funnels, likely to fall over. Guy wires today are used to stabilize everything from circus tents to cell phone towers.