Linnet
A lighthouse.
The two that immediately come to mind are the Loch Ness Monster and the Leviathan.
There are only two letters starting with L that I can think of; the Letter of the alphabet, which is "L" and the Word "Letter." As "Letter" is longer than "L" I can only assume that the word "Letter" is the longest letter starting with L. lymphoblastic leukemia
Words starting with L that mean clear are - lucid and limpid.
Neo Natoligist, network anchorman, newsman, Nuclear scientist, neurologist.
LilyLilacLotusLavenderLupin
lonsdale
Liam
Lucozade.
LizzyLanguish ;D
I want to give my company name with starting l,ta,tu mo
The Lut Desert of Iran.
limbic
Linnet
Booth was an actor
A artist and film maker.