"Potter, what do I get if I added powdered root of asphodel to an infuion of wormwood?"
This is the first thing Snape says directly to Harry. But it's not just a question to get him paying attention, no. JKR always has hidden meanings behing everything.
Asphodel is a type of Lily which translates into, "My regrets follow you to the grave."
And when infused with Wormwood it creats a sleeping draught named 'Living Dead' Wormwood itself means absense or bitter regret.
The two meanings brought together mean:
"I bitterly regret Lily's death"
Potterheads, you may now go cry because of all the feels
I found this from another quote. So I googled it & I took the information from a fan-fiction that explained everything.
nmq just really wanted to have it on my profile