Purpose: Key word signing (KWS) entails using manual signs to support the natural speech of individuals with normal hearing and who have communication difficulties. While manual signs from the local sign language may be used for this purpose, some KWS systems have opted for a distinct KWS lexicon. Distinct KWS lexicon typically aims for higher sign iconicity or recognizability to make the lexicon more accessible for individuals with intellectual disabilities. We sought to determine if, in the Belgian Dutch context, signs from such a distinct KWS lexicon (Spreken Met Ondersteuning van Gebaren [Speaking With Support of Signs; SMOG]) were indeed more iconic than their Flemish Sign Language (FSL) counterparts. Method: Participants were 224 adults with typical development who had no signing experience. They rated the resemblance between a FSL sign and its meaning. Raw data on the iconicity of SMOG from a previous study were used. Translucency was statistically and qualitatively compared between the SMOG lexicon and their FSL counterparts. Results: SMOG had an overall higher translucency than FSL and contained a higher number of iconic signs. Conclusion: This finding may support the value of a separate sign lexicon over using sign language signs. Nevertheless, other aspects, such as wide availability and inclusion, need to be considered.