What does apodix mean in Latin?

apodix, a noun, means “female companion; prostitute, courtesan”.

What is the genitive of apodix?

The genitive singular is apodixis. apodix is feminine, third declension.

noun · femininethird declension

apodix f (genitive apodixis)

Medieval Latinfemininefemale companion
Aporiam, sed et atrophiam, patiaris, ut acam / Atervam appodix tua mens sibi congerat eius.Endure both hardship and poverty so that your soul, which is / Your companion, may gather for itself eternal joy.c. 890, Abbo Cernuus, translated by Nirmal Dass, Bella Parisiacae urbis, book 3, lines 69–70:
Medieval Latinfeminineprostitute, courtesan
Cumque abisset ad mercatum, subito instigante diabolo reperit eum una apodix, id est meretrix […]And when he went out to the marketplace, an apodix, that is, a prostitute, incited suddenly by the devil, found him […]11th century, Vita S. Conwoionis Abbatis Rotonensis, chapter 10:

Probably from appendix (“one who depends on another”), attested as ampedix in Late Latin.