The definition is derived from the Latin word that is glossed here (vectigal, DMLBS p. 3605b: ‘tax, duty, tribute’), but which lacks context to further clarify it. DEAF defines the word as ‘certain droit ou impôt sur le poisson’ which may be relevant here (cf. estivagium in DuCange). What appears to be the same word is defined by the DMF as ‘Fait de placer des troupeaux, pour l’été, dans les patûrages de montagne’ (sub estivage, from the etymon aestivare), which does not seem to apply to this attestation.