A slip or a ramp is where a boat berths.
ache
Unit .
You tell me :P
Butt is four letters! It's short for buttocks.
Starts with a
Twix
john Another answer: While "John" is a name, there is no word that ends in "hn" with only four letters.
Iran and Oman are countries. They end with the letters an.
tofu
Four letter words using those letters and ending in 'l' are:haulhealteal
faro
Tomb or Plot.