LOS
LOSABLE
LOSABLENESS
LOSABLENESSES
LOSE
LOSED
LOSEL
LOSELS
LOSEN
LOSER
LOSERS
LOSES
LOSH
LOSING
LOSINGLY
LOSINGS
LOSLYF
LOSLYFS
LOSS
LOSSES
LOSSIER
LOSSIEST
LOSSLESS
LOSSMAKER
LOSSMAKERS
LOSSMAKING
LOSSY
LOST
LOSTNESS
LOSTNESSES

30 words start with LOS.