What does Burettus mean in Latin?

Burettus, a proper noun, means “a surname, equivalent to French Burette”.

What is the genitive of Burettus?

The genitive singular is Burettī. Burettus is masculine, second declension.

In classical Latin, [bʊˈrɛt.tʊs]; in ecclesiastical (church) Latin, [buˈrɛt.tus].

proper noun · masculinesecond declension

Burettus m sg (genitive Burettī)

Classical[bʊˈrɛt.tʊs]Ecclesiastical[buˈrɛt.tus]

New Latinmasculinesingulara surname, equivalent to French Burette
New LatinmasculinesingularPetrus Johannes Burettus (1665–1747), French physician and antiquary
14 κρητικὸν Burettus: προκριτικὸν14 κρητικὸν Burette: προκριτικὸν1895, Γρηγόριος Ν. Βερναρδάκης [Gregorius N. Bernardakis], Plutarchi Chaeronensis Moralia, volume VI (overall work in Koine Greek), Lipsia: Aedes B. G. Teubneri, Περὶ Μουσικῆς [Perì Mousikês], page 513, footnote re line 14:

From French Burette + Latin -us.