This paper presents a new approach for the evaluation of the detection of synonymy relations between terms. The researchers’ goal is to help terminology structuring. This approach exploits the synonymy relationships which have been extracted from lexical resources to infer synonymy links between complex terms. The inferred links are then validated by a human expert in the context of a terminological application. In a previous evaluation on documents dealing with electric power plant, the expert underlined that the most important point is to increase the recall even if the precision is low and if some links are mistyped. This paper reports on new experiments which help to understand how this synonymy detection approach is to be used. Various lexical resources — from general language dictionaries to very specialized semantic information sources- are exploited and compared as bootstrapping knowledge. Results show the complementarity of the different sources.