Happening by accident or chance rather than design. Good luck.
Fortuitous
Courageous behavior, especially in battle. Valor, bravery.
Gallantry
Looking exhausted and unwell, especially from fatigue, worry, or suffering.
Haggard
Of a device or attack designed to cause fires. Napolm, malotow, cocktails, some IEDs.
Incendiary
Naive, simplistic, and superficial. Archaic.
Jejune
A small item kept in memory of the person who gave it or originally owned it.
Keepsake
Using very few words, concise writing or speech.
Laconic
Disturbing and horrifying because of involvement with or depiction of death and injury.
Macabre
One billionth of a second.
Nanosecond
The condition of being overweight.
Obesity