DeGennaro is the Terps' second wideout in their 2020 class so far.
Boone is the Terps' first four-star recruit in their 2020 class.
Thursday was the one-year anniversary of Jordan McNair's death.
McNair's friends still struggle with his absence from their lives.
Locksley was charged with driving while intoxicated, unlawful carrying of a weapon, marijuana possession and terroristic threat.
Smith will join as a redshirt junior with two years of eligibility remaining.
Battle's commit comes just one day after the Terps landed offensive tackle Santana Saunders.
The university is searching for a new head team physician, who will report to the University Health Center.
He joined Mike Locksley's staff as special teams coordinator and inside linebackers coach.