The term for killing minions to accumulate gold and experience in League of Legends is farming.
Farming usually means collecting resources from minion waves, especially by landing the final hit on enemy minions. The last hit awards gold to the champion that secures it, while nearby champions can generally receive experience when minions die. Good farming helps a champion buy items and reach important ability levels.
The term comes from the broader gaming idea of repeatedly gathering predictable resources. In League, farming is most visible in the lanes, where waves travel from each Nexus toward the opposing base. Champions may also farm jungle monsters, although players often distinguish “lane farming” from “jungle farming.”
Farming is not the same as diving, warding, or roaming. Diving means attacking opponents beneath their turret; warding means placing vision; roaming means leaving one’s usual lane to influence another area. Players also use “CS,” meaning creep score, to track how many minions and certain monsters they have successfully last-hit. Strong CS is useful, but safe positioning and map awareness matter too.