This paper introduces a context-sensitive electronic dictionary that provides translations for any piece of text displayed on a computer screen, without requiring user interaction. This is achieved through a process of three phases: text acquisition from the screen, morpho-syntactic analysis of the context of the selected word, and the dictionary lookup. As with other similar tools available, this program usually works with dictionaries adapted from one or more printed dictionaries. To implement context sensitive features, however, traditional dictionary entries need to be restructured. By splitting up entries into smaller pieces and indexing them in a special way, the program is able to display a restricted set of information that is relevant to the context. Based on the information in the dictionaries, the program is able to recognize-even discontinuous-multiword expressions on the screen. The program has three major features which we believe make it unique for the time being, and which the development focused on: linguistic flexibility (stemming, morphological analysis and shallow parsing), open architecture (three major architectural blocks, all replaceable along public documented APIs), and flexible user interface (replaceable dictionaries, direct user feedback). In this paper, we assess the functional requirements of a context-sensitive dictionary as a start; then we explain the program's three phases of operation, focusing on the implementation of the lexicons and the context-sensitive features. We conclude the paper by comparing our tool to other similar publicly available products, and summarize plans for future development.