The headword is present indicative passive, third person singular, of tulo/w, 'make knobbly', 'cover with knobs'; this form is not found in the quotation given and must be extracted from another text.
The glosses relate to two different contexts in which that verb could be used: first, blistered or calloused skin (cf. tau 1150, tau 1154, tau 1156, upsilon 650); second, an artefact thickened or reinforced with studs. See e.g. Herodotus 7.63, and generally LSJ s.v.
[1] The headword and glosses are derived from the Synagoge tau288 (Cunningham), which is also the source for Photius, Lexicon tau545 Theodoridis (Porson 609.25).
[2] Roos 10, cited by Adler, suggests that the quotation belongs to Eunapius (see similarly omicroniota 183 and chi 147). If correctly ascribed, then 'Parthian' is likely to be an archaizing ethnonym for Sasanian Persians. Other quotations relating to Parthian military equipment have been conjecturally assigned to Arrian's lost Parthica (see theta 439, kappa 274, sigma 278).