The contribution of repeated e-book reading with and without word explanation support and its effect on receptive and expressive word learning among preschoolers was examined. Seventy-eight kindergartners were randomly divided into an experimental and a control group. The experimental group received two individual reading sessions of an e-book with a dictionary that provided word explanations. The children clicked on hotspots which provided the explanation two more times. The children thus heard the meaning of the word three times in each session, with a total of six times. Not all difficult words received a dictionary explanation. The control group received the regular kindergarten program. The children's receptive word learning, word explanation and production of focal words were tested pre and post intervention. An improvement in all dependent measures was found post-intervention, compared to the control group. The dictionary in the e-book supported not only receptive word learning, but also word explanation. Words that received a dictionary explanation supported word learning better than words which were not included in the dictionary. Furthermore, receiving support six times was more effective than three times. Educational implications are discussed.