In this current metaverse era, Arabic learning containing mufradat has not applied construct 2 media in the learning process so far. When viewed from the media, it will certainly match to the current metaverse era, and its application is also accessible. This study aims to design an Arabic vocabulary learning medium and to determine the feasibility of developing an android-based KOSBARAB learning medium to be applied in Arabic subject for 5D MI Bahrul' Ulum Tambakberas Jombang students. The research method used is Research and Development (R&D) with a development model from Borg and Gall, which consists of 10 stages. Research instruments include observation, interviews, questionnaires, and trials. Data from experts’ and respondents' questionnaires were examined using assessment indicators. The study results in 1) the success of developing KOSBARAB learning media, 2) the "very valid" quality of KOSBARAB product based on the assessment by a media expert and two material experts, 3) the "very valid" quality of KOSBARAB product based on the assessment of classification trials on a small and large scale. It shows that students are curiously interested in using KOSBARAB product, and it certainly can increase the basic level of Arabic vocabulary of 5D students of MI Bahrul' Ulum Tambakberas Jombang.