Loneliness, Solitude
Noun, な adjective, and の adjective
こどく
ずっと孤独な人生を送ってきたんです。
I’ve always led an isolated life.
An orphan who's alone is trapped in a world of isolation and loneliness. Having no parents is hard enough, but not having anyone else is even lonelier.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.