taper
The tapering steel columns that support the glass curtain wall are perforated with hexagons.
During a recent flight, Wolf nudged the control stick and his two-seat sailplane banked left, its long tapering wings cutting through the warm air.
We could see the tapering shape of the Qutb Minar, the victory tower erected by the first Muslim sultan.

SMART Vocabulary: related words and phrases

Becoming and making smaller or less
abridgment
attenuate
attenuated
attenuating
attenuation
compress
contraction
dwindle
dwindling
ease
ease someone's mindidiom
ease up/off
halve
recede
reduce
reducible
reduction
resize
trough
tumble

You can also find related words, phrases, and synonyms in the topics:

Narrow and thin