Merriam-Webster's Collegiate Dictionary:
subjunctive
subkingdom
sublate
sublation
sublease
sublet
sublethal
sublethally
sublieutenant
sublimable
sublimate
sublimation
sublime
sublimely
sublimeness
sublimer
subliminal
subliminally
sublimity
subline
sublingual
subliterary
subliterature
sublittoral
sublunar
sublunary
subluxation
submachine gun
submandibular
submarginal
submarine
submariner
submaxillary
submediant
submerge
submerged
submergence
submergible
submerse
submersed
submersible
submersion
submetacentric
submicrogram
submicron
submicroscopic
submicroscopically
submillimeter
subminiature
submiss
submission
submissive
submissively
submissiveness
submit
submitochondrial
submittal
submucosa
submucosal
submultiple
submunition
subnormal
subnormality
subnormally
subnotebook
subnuclear
suboceanic
suborbital
suborder
subordinate
subordinately
subordinateness
subordinating
subordination
subordinative
subordinator
suborn
subornation
suborner
subotica
subphylum
subplot
subpoena
subpoena ad testificandum
subpoena duces tecum
subpolar
subpopulation
subpotency
subpotent
subprincipal
subproblem
subprofessional
subprogram
subregion
subregional
subreption
subreptitious
