The smell it makes. Plus, there are probably many more we can think of. So, our representation has to be very flexible. Morphemes are the meaning units. The more morphemes you have in a word you're looking up, the slower it is.
Nouns are faster than verbs.
If it's present, access is slower. Now that we know what meaning is and what affects accessing meaning, we need to think about how it's organized. A. Network models. Your concepts are organized in a collection of nodes and links between the nodes. The farther apart two concepts are the less related they are.