lag bolt(n = noun.artifact) lag screw - a heavy woodscrew with a square or hexagonal head that is driven in with a wrench;
is a kind of woodscrew

bolt, bolt cutter, bolt down, bolt hole, bolt of lightning, bolt out, carriage bolt, expansion bolt, jet lag, lag, lag b'omer, lag behind, lag screw, machine bolt, nut and bolt, safety bolt, stove bolt, time lag, toggle bolt