infeliz

infeliz
een-feh-lees'
unhappy, unfortunate, wretched
Examples
1. Finalmente tuve que romper con mi novio porque simplemente era una persona demasiado infeliz.
I finally had to break up with my boyfriend because he was simply too unhappy a person.
 
2. Mi abuelo logró mucho en su vida a pesar de tener una niñez infeliz.
My grandfather accomplished a lot in his life despite having a wretched childhood.
 
Notes
"Infeliz" can also be used as a noun to refer to an unhappy or miserable person, as well as an ingenuous person.