vain
UK: veɪn | US: veɪn
adj. having an excessively high opinion of one's appearance or abilities
adj. producing no result; futile
adj. (archaic) empty or worthless
The word "vain" traces back to the Latin vanus, meaning "empty" or "worthless." Over time, it evolved in Old French as vain, retaining the sense of emptiness but also acquiring connotations of futility and excessive pride. The modern English usage reflects both meanings: the futility of an action ("a vain attempt") and the emptiness of superficial pride ("vain about his looks"). The logical progression ties emptiness to lack of substance, whether in results or character.
She was too vain to wear glasses, even though she needed them.
All their efforts to save the business proved vain.
He made a vain promise to return by noon.
The vain politician cared more about his image than his policies.
It’s vain to resist the inevitable changes of time.