By oneself, solitary.
Lacking peers who share one's beliefs, experiences, practices, etc.
Not requiring anything further; merely.
By oneself; apart from, or exclusive of, others; solo.
Without outside help.
Used to emphasize the size or extent of something by selecting a subset.
Not permitting anything further; exclusively.
Of a person: forthright; honest.
Of rain: pouring straight down.
Thoroughly.