Mystique

n.joyful, thoughtfulwarm

What it means

An attractive aura of mystery surrounding a person, place, or subject.

Reach for it when describing fascination created partly by what remains unknown, without treating secrecy as proof of merit

The closed observatory retained its mystique long after newer telescopes opened.

playful
spell
figurative enchantment captures the emotional hold
not when Spell is theatrical and can imply manipulation rather than earned interest.
everyday
mystery
what is unknown is the plain central fact
not when Mystery alone may be alarming or neutral, without mystique's attraction.
warm
aura
a distinctive atmosphere seems to surround the subject
not when Aura may be comforting or threatening and does not require fascination.
professional
fascination
strong sustained interest is the observable response
not when Fascination names the effect on people rather than the quality producing it.
formal
cachet
prestige increases desirability within a social group
not when Cachet depends on status and may survive after the mystery disappears.
formal
enigma
the subject itself is difficult to understand
not when An enigma can frustrate or repel, whereas mystique is attractive.
literary
allure
subtle attraction draws interest
not when Allure need not involve mystery and can be openly sensual.
literary
glamour
idealized charm and prestige create appeal
not when Glamour can be carefully manufactured and need not conceal anything.

air of mystique
An air of mystique surrounds the unsigned paintings in the chapel.
retain mystique
The island can retain mystique without inventing stories about its residents.
add to the mystique
Rare winter openings add to the mystique of the mountain garden.

The definition and the example on this page are written here. The dictionaries above ground which meaning is being described, not the wording.