Ordinary, simple, vanilla
Possibly "unadorned"
"Similar" is a word that means nearly the same as "like."
Precipitation
boundary
Certify.
Height.
Plain, flatland, tundra...
A word that means the same or nearly the same as another word, such as bucket and pail.
dealing with managing
Enlist.
Unattractive, knit, prairie, unadorned are synonyms for the various meanings of "plain".
I believe you are looking for the word synonym.
A synonym for seized is grabbed.