has legs Share definition Flag Used to judge an idea. Means "is useful" or "has relevant meaning" or "is applicable" or "thats a good idea". dont know origin. Example: in response to "We could try one more test." say "That has legs" has legs by HoJoXo February 19, 2018 0 0 Get merch Get the has legs mug. Buy Now — $32.95 See more merch