NIP
NIPA
NIPAS
NIPCHEESE
NIPCHEESES
NIPPED
NIPPER
NIPPERED
NIPPERING
NIPPERKIN
NIPPERKINS
NIPPERS
NIPPIER
NIPPIEST
NIPPILY
NIPPINESS
NIPPINESSES
NIPPING
NIPPINGLY
NIPPLE
NIPPLED
NIPPLES
NIPPLEWORT
NIPPLEWORTS
NIPPLING
NIPPY
NIPS
NIPTER
NIPTERS

29 words start with NIP.