If you wield a tool or a weapon, you handle it effectively. Picture a gallant knight wielding a sword or a skillful chef wielding a whisk.
You don't just have to wield something physical; you can also wield or exert influence or authority. Wield is frequently followed by the word power. If you were a king, you could wield great power in your kingdom — exerting your influence over everything from food rations to castle upkeep. As it is, though, you might just wield power over your pet goldfish. Note: wield follows the i before e, except after c spelling rule.