I believe aggradire is an archaic form for aggradare, "to please". Gradire also means "to enjoy". The Italian word for "to aggress" is aggredire.
Having studied both Italian and English literature in high school, I can confirm that 17th century Italian is more understandable for a native speaker than 17th century English is. But I am naturally biased because I am a native Italian speaker.
Thank you for the correction! So, unsurprisingly, Drake is correct, and my Spanish-based intuition was wrong, as was Google Translate. ("Please" makes more sense in context, too.)
In Spanish we have agradecido, "grateful", which I suppose must be cognate, though the underlying verb agradecer is not in my Spanish-as-second-language vocabulary. https://dle.rae.es/agradecer
Having studied both Italian and English literature in high school, I can confirm that 17th century Italian is more understandable for a native speaker than 17th century English is. But I am naturally biased because I am a native Italian speaker.