a lone wolf.
a lonely existence.
a lonely fisherman stood on a tuft of gravel.
a lonely soul.
a lonesome pine.
a man of a solitary disposition.
a solitary instance of cowardice.
a solitary speck in the sky.
a solitary traveler.
a solitary walk.
an only child.
he was alone when we met him.
she is alone much of the time.
the lone doctor in the entire county.
the lone skier on the mountain.
the sole example.
the sole heir.