奸

adjective: treacherous, evil; wicked, crafty/sly
奸, 奸詐

The character 奸/姦 carries several distinct senses under the same reading (treacherous/evil/traitor vs. to commit adultery/rape); the general adjective sense was chosen as primary, but Teochew compounds listed on the page (e.g. 捉奸見床) point toward the adultery-related sense also being salient.