Donovan Mitchell's nickname is now recognized by Dictionary.com.
The website added "Spida" as an official entry under the slang category, defining it as: "A basketball species usually found above the rim; equipped with superhuman senses, shot-slinging abilities, and unrivaled bounce."
They also provided an alternate definition: "Nickname of Donovan Mitchell, record-breaking shooting guard for the Utah Jazz and contender for NBA's 2018 Rookie of the Year."
Dictionary.com goes on to explain the origin of "Spida," and includes a photo of Mitchell's famous rookie hoodie, which features their definition of the word.