Although nouns are easily learned in early stages of lexical development, their role in adult word and text comprehension remains unexplored thus far. To investigate the role of different word classes (open-class words: nouns, adjectives, verbs; closed-class words: pronouns, prepositions, conjunctions, etc.), 141 participants read a transposed German text while recording eye movements. Subsequently, participants indicated words they found difficult and reproduced the story. Then, participants were presented an untransposed text version while also tracking eye movements. Word difficulty, subjectively assessed by an interview and objectively by eye movement criteria (general fixation rate, number of fixations on specific words), text comprehension scores, and regressive fixations from one word class to another in the transposed text indicated that the noun was the most influential word class in enhancing the comprehension of other words. Developmental, intercultural, and neurophysiological aspects of noun dominance are discussed.