The Collaborative International Dictionary
adj. constructed so as to tip up or out of the way; "the little tip-up seat of the taxi"
A tip-up is a device used while ice fishing to suspend live or frozen bait at a set depth through a hole drilled in the ice with an auger, and detect when a fish strikes, without having to be in contact with this piece of gear. When a fish does take the bait, a flag "tips up" or the flag can "tip down" to signal the angler that a fish has taken his bait. Because the angler does not need to stay with his line and can see that the flag at a distance, he or she is able to cover a larger area than with just an ice fishing rod.
Usage examples of "tip-up".
I cut the rest of the holes, baited my lines, adjusted the tip-ups, then stood there waiting on the ice.