Sound-meaning correspondences produced by an infant were studied under conditions of early rampant homonymy (i.e., production by a very young child of a small set of noncontrastive surface forms or phonetic sequences to refer to objects/events that on the basis of adult standards require the production of numerous contrasting surface forms). The speech of a male twin (H), who was 1;4 years at the outset of the initial three months of evaluation, was assessed. Data were drawn from a 10-month study of the infant, his fraternal twin, and their mother. The data were analyzed in the framework of word-based phonology and phone class analysis. Phone classes for H were restricted to voiced bilabial (/b/ and /m/), alveolar (/d/), and velar (/g/ and /h-phi/) sound segments. H's productions were restricted to a point where high levels of homonymy would be expected. Three referents (e.g., cookie, book, and apple), which at first were produced with distinctive and resolvable surface forms, coalesced and took on a common surface form. H's tolerance for homonymy, therefore, could not be tied to the absence of resolvability. Attempts were made to analyze a representative selection of H's homonymous forms on the basis of both phonetic substance and referential substance. It is suggested that a charge of relative incompetence at the phonetic level does not adequately explain homonymy. Analyses that link homonymy at least in part to the phenomenon of overextension demonstrate that a young child with few productive surface contrasts is capable of controlling more of the ambient language than is reflected in his first linguistic performance. (SW)