Background: The metalinguistic ability to cope with homonyms, that is, words having multiple unrelated meanings, emerges rather late in the course child language development. It is associated with specific neural activity and related to academic achievement and second language learning. This study is about homonyms that are at the same time homographs and homophones. For clinical purposes, it would be useful to have additional normative data on acquisition. Aims: The goal of this study was to develop a measurement protocol for mastery of multiple literal meanings of homonymous nouns and to document Dutch-speaking children's performances during the final stages of child language development. Age and gender effects as well as the correlation with type token ratios in spontaneous speech will be examined. Methods & Procedures: Twenty-one words having only one literal meaning, 19 homonyms, and 20 pseudo-words were presented to 801 children from the fourth, the fifth and the sixth or final grade of regular elementary schools. These children had no hearing or learning difficulties. Each test item was presented simultaneously in writing on a screen and as a spoken word. The task was to put each word into one of three possible categories: no meaning, just one literal meaning and more than one literal meaning. After item analysis, only the best items from the original corpus of 60 words were used to calculate a final score with. A 3 x 2 analysis of variance (ANOVA) was calculated to assess age and gender effects. The correlation between type token ratio results and multiple meaning mastery results was determined. Outcomes & Results: The ability to define a word correctly as homonymous clearly develops rather late in the course of language development and significant progress is being made during final elementary school years. Significant age and gender effects were found. The correlations with type token ratio results did not reach significance levels. Children were very accurate in identifying pseudo-words as meaningless items. Conclusions & Implications: Further research is needed to find out whether there actually is a genuine gender effect in the ability to reflect on words with multiple meanings. This ability is different from what is traditionally defined as active or passive vocabulary, because of the metalinguistic dimensions of the task. The findings in this study underpin the need for further exploration of metalinguistic aspects of vocabulary growth and language development in general, and for the development of appropriate test tools. A screening of multiple meaning mastery may be a valuable procedure to detect individuals in need of therapy and to help school counsellors in formulating a school career advice. (Contains 1 table and 1 figure.)