Medical language, as many technical languages, is rich with morphologically complex words, many of which take their roots in Greek and Latin-in which case they are called neoclassical compounds. Morphosemantic analysis can help generate definitions of such words. This paper reports work on the adaptation of a morphosemantic analyzer dedicated to French (DériF) to analyze English medical neoclassical compounds. It presents the principles of this transposition and its current performance. The analyzer was tested on a set of 1,299 compounds extracted from the WHO-ART terminology. 859 could be decomposed and defined, 675 of which successfully. An advantage of this process is that complex linguistic analyses designed for French could be successfully transferred to the analysis of English medical neoclassical compounds. Moreover, the resulting system can produce more complete analyses of English medical compounds than existing ones, including a hierarchical decomposition and semantic gloss of each word.