ballistarium

• (Classical) IPA^(key): /bal.lisˈtaː.ri.um/, [bälːʲɪs̠ˈt̪äːriʊ̃ˑ]
• (modern Italianate Ecclesiastical) IPA^(key): /bal.lisˈta.ri.um/, [bälːisˈt̪äːrium]

From ballista (“ballista”) +‎ -ārium (“place for”).

• bālistārium

ballistārium n (genitive ballistāriī or ballistārī); second declension

1. a ballista emplacement (the place where the ballista is worked)
2. a ballista

Second-declension noun (neuter).

¹Found in older Latin (until the Augustan Age).

• “ballistārĭum (balist-)”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• ballistārĭum in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.: “206/1”
• “ballistārium” on page 224/2 of the Oxford Latin Dictionary (1st ed., 1968–82)

See the etymology of the corresponding lemma form.

ballistārium m

1. accusative singular of ballistārius