Clay.
lode
lode
dam in a river
Avon
Ural
shoal
deposit
A four letter word starting with the letter a is able.
Reserve
It depends on what you mean by 'four letter word'. Thea has four letters, so yes it is. It is not a swear word, so it's not that kind of 'four letter word'.
A four letter word for 'in addition to' is also.
A four letter word for Seizures is moon