Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
in-dēclīnātus, a, um, adj., unchanged, constant (Ovidian). Of persons: qui perstas indeclinatus amico, Ov. P. 4, 10, 83.
Of things: amicitia, Ov. Tr. 4, 5, 24.