The emergence of a distinct Gen-Z sociolect, often termed "Genzie" or "Internet Slang," represents one of the most rapid and transformative linguistic developments of the digital age. This language is not a random collection of slang but a complex, rule-governed system born from the intersection of technology, social change, and identity formation. A comprehensive, data-driven analysis of its historical evolution, structural properties, and socio-pragmatic functions is critical to understanding contemporary communication, as it reflects fundamental shifts in how a generation conceptualizes interaction, community, and self-expression. This study aims to deconstruct the Gen-Z sociolect by tracing its historical development over a key 36-month period (2021-2023), analyzing its core structural components (lexical, semantic, syntactic, multimodal), and explaining its social functions within digital communities. The research seeks to move beyond anecdotal description to provide a rigorous, empirical account of this dynamic linguistic phenomenon, thereby establishing a benchmark for the academic study of internet-native dialects. We position this sociolect not as a degradation of Standard English, but as a legitimate linguistic innovation worthy of serious scholarly attention, with its own internal logic and systemic coherence. A mixed-methods, diachronic approach was employed, integrating the scale of computational linguistics with the nuance of qualitative discourse analysis. A large-scale corpus of approximately 6000 posts was compiled from three core platforms—Twitter/X, Instagram, and TikTok—across the 12-month timeframe, ensuring a representative sample of public-facing Gen-Z communication. Computational linguistics methods were used for quantitative analysis, including time-series modeling for lexical diffusion, diachronic word embeddings for semantic shift, and supervised machine learning for stylometric identification. This was complemented by qualitative discourse and pragmatic analysis of a stratified sample of posts to understand language-in-use, focusing on the interplay between text, image, and platform-specific conventions. The analysis reveals a clear, platform-influenced historical trajectory for Gen-Z language, with terms originating on niche, visually-driven forums like TikTok and Twitch before achieving mass diffusion on the text-centric environment of Twitter and finally being normalized on the broader social canvas of Instagram. We identified and modeled three primary mechanisms of lexical creation: neologism (e.g., "skibidi," "gyatt"), semantic reappropriation (e.g., "cap," "based," "fire"), and phono-semantic matching from online cultures (e.g., "ratio," "L + RIP bozo"). Gen-Z language is a legitimate and sophisticated dialect of the digital era, a natural linguistic adaptation to a hyper-connected, attention-economy-driven world. Its evolution is not chaotic but follows predictable patterns of cultural transmission that are dramatically amplified and accelerated by social media algorithms. Its structure efficiently manages cognitive load in fast-paced digital environments while its primary functions are the performance of a specific digital identity, the creation and policing of digital community boundaries, and a form of resistance to traditional linguistic and social norms.