The word "偷偷摸摸" is formed through a common Chinese morphological pattern called reduplication, specifically an AABB structure, where the base morphemes "偷" (tōu, meaning to steal or act stealthily) and "摸" (mō, meaning to feel or fumble) are each doubled. This doubling intensifies and extends the meaning: "偷偷" amplifies the sense of secrecy and sneakiness, while "摸摸" evokes furtive, hesitant, or groping movements. Combined, the compound vividly depicts a manner of acting in a furtive, clandestine, and often shamefully evasive way, conveying both the intention of secrecy and the clumsy, nervous behavior that accompanies it.