Many studies have addressed how linguistic complexity affects processing in online comprehension. However, little attention has been given to the relationship between different types of semantic complexity. We investigated two kinds of complexity that have previously been studied separately: coercion, where the meaning of a lexical item is shifted by context, and lexical semantic complexity, which describes the inherent semantic complexity of a lexical item. To compare their processing mechanisms, we used psychological verbs, which divide into two classes with different degrees of lexical semantic complexity, and also participate in a previously uninvestigated coercion, inchoative coercion. Using self-paced reading, we find a reading delay associated with both types of complexity, supporting theories that strongly connect representational complexity and processing. A subsequent magnetoencephalography study showed a distributed fronto-temporal effect around 300500 ms for coercion but not for lexical semantic complexity. Our results conform with prior studies showing a prefrontal effect of coercion and suggest that lexical semantic complexity is processed via different mechanisms than coercion.