1) Factory whistle, at noon 2) Flautist 3) Horn blower 4) Horn player 5) Horn player, essentially 6) Horn-blower 7) Impatient motorist 8) Many a cabbie 9) Many a manhattan cabbie 10) Many a train engineer 11) Taxi driver, often 12) Whistle blower 13) Young man with a horn 1) Horn 
• (n.) One who toots; one who plays upon a pipe or horn.
Toot'er noun One who toots; one who plays upon a pipe or horn. B. Jonson.