Semantics, the study of the meaning of words, is the sum of the basic elements of four skills, namely, reading, writing, speaking and listening effectively. The knowledge of vocabulary words in lexico-semantics, on the other hand, is essential in every grade level, subject area and assessment for every student. In order to improve students' efficiency in the realm of learning and utilizing them in appropriate instances, we must give them means to decode unfamiliar words through such elements called "affixes" and "roots". Based on theories of Constructivism and Bloom's Taxonomy, and in the context of teaching all components of a language and arts curriculum, teaching such common roots and affixes is an effective strategy that would secure them a rich vocabulary. This presentation will call attention to an alternative dimension to traditional vocabulary teaching based on giving definitions of words or eliciting or deducing meaning from context. According to this methodology, first an awareness is given to students that the English words are essentially borrowings from other languages mostly with Latin or Greek origins (roots) formed by additions to them by parts (affixes) attached to their front and end. So by guessing the meaning of unknown words by such elements, learners are assumed to grasp the idea of the whole word. This presentation will serve as an introduction to the issue of the nature and functions of word etymology with semantics and lexico-semantics in learning English vocabulary items both for learners and teachers alike. Keywords: semantics, lexico-semantics, affix, prefix, suffix, root.