As contact languages, pidgins and creoles arise in mixed linguistic environments. Drawing much of their vocabularies from one, frequently European, language and – to a lesser extent – from a number of indigenous languages, they have lexicons that are reduced in comparison with those of their lexifiers. To compensate for the poor lexification, pidgin and creoles create novel polysemy-based extensions of lexical items or develop periphrastic constructions equivalent of the missing lexical roots. Assuming a cognitive linguistic perspective, which emphasizes the role of conceptualization in the construction of meaning and the figurative character of concepts, the paper deals with the lexicons of Nigerian Pidgin English and Tok Pisin, two contact languages representative for the Atlantic and the Pacific – the two major areas of linguistic contact. The analysis focuses on the first of the above-mentioned compensation strategies. It is argued that (i) the expressions borrowed from English and various indigenous languages acquire senses that are absent in English; (ii) the new senses are frequently based on metonymy, which serves as a major polysemy-based strategy of lexicon extension; (iii) most of the novel lexical extensions fall within the metonymic patterns that are well-established in English.