In recreational fishing terminology, the hookset or setting the hook is when an angler makes a sudden lifting motion to a fishing rod in order to pull the line and anchor the fish hook firmly into the mouth of a fish once it has gulped in the hook along with the bait/lure.
In order to securely tether the fish with the line, sufficient force is needed to drive the hook point through the epithelium into the connective tissue and muscle of the fish's mouth, preferably under and around a jaw bone. If this were not achieved, while it is still possible for the hook to anchor itself in to the fish's oral tissue, the likelihood of successfully landing the fish is reduced since, without the hook piercing to enough depth, the fish can shake the hook loose during struggle, spit it out and then escape. A deep enough hookset also catches more tissue (thus making it less likely to tear through the flesh), and transfers most of the deformational stress longitudinally along the shank portion of the hook (where it also has the greatest tensile strength), instead of onto the bend (the curved portion of the hook) where the hook is more vulnerable to deflection and slippage when pulled by the line.
