In the Western Semitic domain, Hebrew, Syriac and Arabic, the youngest languages of this group, share terms that present themselves as morphophonologically similar and homonymous: and, respectively, that illah, that is to say, that of the other Member States, and of the other Member States. The latter, from the previous, has two meanings in Arabic, ‘illness’ on the one hand and ‘cause’ on the other. That is also the case for the Greek term aitía, which is the equivalent of those semmitic terms. However, it is difficult to link these two meanings to each other, and the classic explanation for Arabic is to say that the latter would detract from the former. This study seeks to show that, contrary to what some argue, not only the Greek term, but also its Syriac and Hebrew equivalents have only the meaning of ‘cause’. She also suggested that the Syriac and Hebrew terms should not be regarded as the descendants of a common proto-semitism (nothing comparable could be reported in akkadien), but rather as the likely fruit of a loan made in the low Latin region: hence, the meaning of ‘cause’ is not so much the meaning of ‘cause’ to be explained in Arabic, but rather that of ‘illness’, and, contrary to what has been argued, it is certainly the meaning of ‘cause’ which is the first and fundamental meaning and not that of ‘illness’, which in that case certainly explains his employment in Arabic grammar.