What does Ancalitēs mean in Latin?

Ancalitēs, a proper noun, means “A tribe of Britain mentioned by Caesar in his commentaries”.

What is the genitive of Ancalitēs?

The genitive singular is Ancalitum. Ancalitēs is masculine, third declension.

In classical Latin, [aŋ.kaˈliː.teːs]; in ecclesiastical (church) Latin, [aŋ.kaˈliː.tes].

proper noun · masculinethird declension

Ancalitēs m pl (genitive Ancalitum)

Classical[aŋ.kaˈliː.teːs]Ecclesiastical[aŋ.kaˈliː.tes]

A tribe of Britain mentioned by Caesar in his commentaries
Trinovantibus defensis atque ab omni militum iniuria prohibitis, Cenimagni, Segontiaci, Ancalites, Bibroci, Cassi legationibus missis sese Caesari dedunt.The Trinobantes being protected and secured from any violence of the soldiers, the Cenimagni, the Segontiaci, the Ancalites, the Bibroci, and the Cassi, sending embassies, surrendered themselves to Caesar.c. 52 BCE, Julius Caesar, Commentarii de bello Gallico 5.21

Ancălĭtes, um, m.,

I. a people in Britain, otherwise unknown, Caes. B. G. 5, 21.