This study attempted to investigate the effects of two forms of text-based glosses, namely dynamic and non-dynamic glosses, on vocabulary learning of EFL learners. To this end, two experimental groups and one control group, each comprising 25 participants, took part in the study. The DIALANG test was employed as a homogenizing tool to ensure the right proficiency level of the participants. During ten treatment sessions, the participants were presented with some passages that included a number of unknown words by the researchers via WhatsApp application. The participants in the dynamic glossing condition were given a set of gradual hints and prompts, from the most implicit to the most explicit, to help them identify the correct definition of unknown words. In the non-dynamic glossing group, learners were provided with their first language (L1) definition of the words following their request. All the groups completed two immediate and two delayed posttests. Results provided evidence for the benefits of both dynamic and non-dynamic glossing conditions. Besides, the results revealed that the dynamic glossing condition was superior to the non-dynamic glossing condition for L2 vocabulary learning. Discussion and implications of the study were elaborated in the discussion and conclusion sections in full details.