the.com/temperamental
Reliably unreliable, like a vintage car that runs on mood instead of gasoline.
means Prone to sudden, unpredictable shifts in mood or behavior, often touchy or hard to please.
from From temperament, via Latin temperamentum, meaning a proper mixing — back when personality was thought to be a literal blend of four bodily humors.
Humoral rootsOnce meant your blood-bile-phlegm balance, not your tantrums.
Objects tooEngines and printers earn this insult honestly.
Temper twinsShares ancestry with temper, temperature, and temperance.