of a kind
Of some sort, but not a typical or perfect specimen. For example, They have a backyard of a kind, but it's tiny. This usage was first recorded in 1895. For a synonym, see of sorts.
one of a kind. A unique instance, as in There are no others like it; this hybrid daylily is one of a kind, or She's extremely generous, one of a kind. Also see two of a kind.