Lewis & Short

lēgātīvus, a, um, adj. [1. lego].

  1. I. Of or relating to an embassy (post-class.): viaticum, or absol. lēgātīvum, i, n., an ambassador’s expenses: viaticum, quod legativum dicitur, Dig. 50, 4, 18, § 12: his, qui non gratuitam legationem susceperunt, legativum ex forma restituitur, ib. 50, 7, 2, § 3 (al. legaticium).
  2. II. Left by a last will or testament, Inscr. Orell. 3817.