A QUIET PROTEST
Invideo, the root of our words envy and invidious, means to hate. Natalis, like its descendants in the romance languages, means birthday. Adsum is one of the verbs derived from sum, to be. The ad- here means present, or at hand, or simply here. It conjugates like sum: adsum, I am here; ades, you are here, and so on.
The beautifully conversational opening of Sulpicia’s second poem should give you no trouble.
Invisus natalis adest…
My stupid bloody birthday is here.