Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
tūtāmentum, i, n. [1. tutor], a means of defence, defence, protection (rare; not anteAug.), Liv. 21, 61, 10: circumspiciens tutamenta sermonis, App. M. 1, p. 105; Vulg. 1 Macc. 14, 37.