Two experiments are reported that investigated the effect of concreteness on the ability to generate words to fit sentence contexts. When participants attempted to retrieve words from dictionary definitions in Experiment 1, abstract words were associated with more omissions and more alternates than were concrete words. These findings are consistent with the view that the semantic-lexical weights in the word production system are weaker for abstract than for concrete words. We found no evidence that greater competition from semantic neighbors was an additional reason why abstract words were harder to produce. Participants also reported more positive tip-of-the-tongue states (TOTs) when attempting to produce abstract words from their definitions, consistent with more phonological retrieval problems for abstract than for concrete words. In Experiment 2, participants attempted to generate words to fit into a sentence that described a specific event. The difference between the numbers of abstract and concrete words recalled was significantly smaller in the event condition than in the definition condition, and evidence no longer emerged of greater phonological retrieval failure for abstract words. Overall, the results are consistent with the view that the semantic-lexical weights, but not the lexicalphonological weights, are weaker for abstract than for concrete words in the word production system. Keywords Concreteness effect . Word production . Tip-of-the-tongue statesIn this study, we investigated the way in which rated concreteness influences the processes that are involved in word production. Experiments examining the effects on word production of variables such as frequency and age of acquisition have often employed tests of picture naming (e.g., Johnston, Dent, Humphreys, & Barry, 2010). Because it is not feasible to present abstract words in pictorial form, a few studies have instead used definition tasks to compare concrete and abstract word retrieval (Allen & Hulme, 2006;Hanley & Kay, 1997;Newton & Barry, 1997). Participants are presented with dictionary definitions of concrete and abstract words, and they attempt to recall the word that fits each definition. Allen and Hulme reported significantly better concrete than abstract word production on this task, even though their sets of concrete and abstract words were matched for frequency, morphemic complexity, age of acquisition, familiarity, neighborhood size, and word length.As Allen and Hulme (2006) pointed out, generating words from dictionary definitions involves several distinct processes. It first requires access to a target word's semantic representation in memory. In terms of a model of word production such as that put forward by Foygel and Dell (2000), activation of the word's lexical representation can then take place from its semantic representation, followed by activation of the word's phonological features. Gollan and Brown (2006) argued that the kinds of errors that participants make during word production make it possible to distinguis...