What does violāceus mean in Latin?

violāceus, a adjective, means “violet (coloured)”.

How do you pronounce violāceus?

In classical Latin, [wi.ɔˈɫaː.ke.ʊs]; in ecclesiastical (church) Latin, [vi.oˈlaː.t͡ʃe.us].

adjectivefirst/second-declension adjective

violāceus (feminine violācea, neuter violāceum)

Classical[wi.ɔˈɫaː.ke.ʊs]Ecclesiastical[vi.oˈlaː.t͡ʃe.us]

adjectiveviolet (coloured)
Mē . . . iuuene uiolācea purpura uigēbat, cuius lībra dēnāriīs centum uēnībat, nec multō post rubra Tarentīna. huic successit dibapha Tyria, quae in lībrās dēnāriīs mīlle nōn poterat emī. hāc P. Lentulus Spinthēr aedīlis curūlis prīmus in praetextā ūsus inprobābātur. quā purpurā quis nōn iam . . . trīclīniāria facit?In my day, violet-colored (i.e., dark) purple was in esteem, and you could buy it for a hundred denarii a pound, and shortly after that, the red Tarentine purple. Then appeared double-dyed Tyrian, which you by the pound couldn't buy with a thousand denarii. Publius Lentulus Spinther, when he was aedile of the curule seat, used this purple in his praetexta toga, first one to do that, and he was criticized for it. This purple, who doesn't now make already dining room cushions with it?c. 110 BCE – c. 25 BCE, Cornelius Nepos, Fragments 27.2

singular
form	masculine	feminine	neuter
nominative	violāceus	violācea	violāceum
genitive	violāceī	violāceae	violāceī
dative	violāceō	violāceae	violāceō
accusative	violāceum	violāceam	violāceum
ablative	violāceō	violāceā	violāceō
vocative	violācee	violācea	violāceum

plural
form	masculine	feminine	neuter
nominative	violāceī	violāceae	violācea
genitive	violāceōrum	violāceārum	violāceōrum
dative	violāceīs	violāceīs	violāceīs
accusative	violāceōs	violāceās	violācea
ablative	violāceīs	violāceīs	violāceīs
vocative	violāceī	violāceae	violācea

vĭŏlācĕus, a, um, adj. viola, II.,

I. violet-colored, violet: purpura, Nep. ap. Plin. 9, 39, 63, § 136: flos herbae, Plin. 22, 18, 21, § 47: gemma, id. 37, 10, 61, § 170.

From viola (“violet flower”) + -āceus.