Abstract-Vocabulary learning is indispensable in the process of second language (L2) learning and plays a pivotal role in this regard. At the heart of this issue is the homonymous conflict, which is more problematic and very difficult to deal with. Therefore, the current study was undertaken to cast a little bit of light on homonyms instruction in the area of learners' L2 vocabulary development and retention. In this vein, four intact classes of Iran Language Institute (ILI) comprised of 46 young female EFL learners aged from 9-10 years old enrolled in the present study whose English proficiency level was elementary. Signing the Assent form, the participants were given a proficiency test for homogenizing. They were divided into two groups of experimental and control. The former group favored the explicit, simultaneous and concurrent homonymous set of words instruction; however, the latter one encountered the accidental and incidental homonyms instruction through various texts. The results obtained from vocabulary achievement test indicated that in the vocabulary development phase, both methods appeared to be significantly effective in the short run, but the participants in the experimental group revealed a better performance. Moreover, after administrating the delayed post-test, the analysis elicited that homonyms instruction significantly hindered the vocabulary recovery and retention of the learners just in the Experimental group three weeks later. Hence, the outcome of this piece of study provided various remarkable implications for teachers to reinforce learners' vocabulary repertoire through context, and led to give some insights into homonyms instruction via metalinguistic awareness.