Words that belong to the same subcategory	E.g., pets; dog, cat, rabbit
Words that have a strong association in the real world	E.g., cat, mouse
Words that share the same first letter	E.g., fish, ferret
Words that share the same first sound	E.g., cat, kangaroo
Words that share the same word	E.g., horse, seahorse
Words that rhyme	E.g. cat, rat

Based on Ledoux et al. [11] and Troyer et al. [24]