tristor: āri,I v. dep. n. [id.], to be sad, grieved, or downcast (very rare): numquam flere, numquam tristari, Sen. Prov. 2, 3; id. Ira, 2, 7, 1.
trīstor, ārī (tristis), intr., s’attrister : Vulg. Reg. 1, 20, 3.