The word 简直 is formed by combining two characters, each contributing a core meaning that merges into a new, unified concept. The character 简 (jiǎn) originally referred to bamboo slips used for writing, carrying connotations of something being simple, brief, or unadorned. The character 直 (zhí) means straight, direct, or upright. When fused, the compound evokes the imagery of something being "simply straightforward" or "direct without complication", metaphorically extending to express the idea of something being so direct and unambiguous that it is virtually or absolutely the case.