vain

vain /ˈveɪn/ adjective
vainer; vainest
vain
/ˈveɪn/
adjective
vainer; vainest
Britannica Dictionary definition of VAIN
1 
[also more vain; most vain] : too proud of your own appearance, abilities, achievements, etc. : conceited
2 
: having no success : not producing a desired result

in vain

: without success : without producing a good or desired result

take someone's name in vain

: to use (a name, especially the name of God) in a way that does not show proper respect

— vainly

adverb