excessively proud of or concerned about one's own appearance, qualities, achievements, etc.; conceited

a vain dandy.

proceeding from or showing personal vanity

vain remarks.

ineffectual or unsuccessful; futile

a vain effort.

without real significance, value, or importance; baseless or worthless

vain pageantry; vain display.

Archaic . senseless or foolish. ?

in vain

without effect or avail; to no purpose

to apologize in vain.

in an improper or irreverent manner

to take God's name in vain.

noun

bootlessness , fruitlessness , unavailingness , unprofitableness , uselessness , vanity , amour-propre , conceit , ego , egoism , narcissism , pride , vainglory