The process of design often involves translating abstract semantic information into visual artifacts. To understand how psycholinguistic properties of semantic prompts impact the design process, we conducted a behavioral study with 515 participants who were asked to design a chair that reflected a prompt word. During the task, participants made various aesthetic and functional choices to realize their design vision. We investigated how semantic richness (imageability and number of semantic neighbors) of prompts and semantic similarity between prompts impacted the characteristics of the final design. Results indicate that different outcome types (functional and geometric) are associated with semantic properties, while prompt similarity is related to outcome differentiability. The results reveal the complex relationship between semantic inputs and human-generated outputs in a creative context, with implications for how multi-modal (text, image, and 3D) systems should be built to complement design activities.