UPGANG
UPGANGS
UPGATHER
UPGATHERED
UPGATHERING
UPGATHERS
UPGAZE
UPGAZED
UPGAZES
UPGAZING
UPGIRD
UPGIRDED
UPGIRDING
UPGIRDS
UPGIRT
UPGO
UPGOES
UPGOING
UPGOINGS
UPGONE
UPGRADABILITIES
UPGRADABILITY
UPGRADABLE
UPGRADATION
UPGRADATIONS
UPGRADE
UPGRADEABILITY
UPGRADEABLE
UPGRADED
UPGRADER
UPGRADERS
UPGRADES
UPGRADING
UPGREW
UPGROW
UPGROWING
UPGROWINGS
UPGROWN
UPGROWS
UPGROWTH
UPGROWTHS
UPGUSH
UPGUSHED
UPGUSHES
UPGUSHING

45 words start with UPG.