decreasing
narrow
acanthoid
acanthous
acicular
acuate
aculeate
aculeiform
acuminate
acute
barbed
coarctation
cone-shaped
conical
constriction
contraction
cornuted
cusped
cuspidate
fastigiate
hispid
horned
horny
mucronate
narrowing
needle-pointed
needle-sharp
pointed
pronged
pyramidal
sharp-pointed
spiculate
spiked
spiky
spined
spinous
spiny
spiry
stricture
taper
tapered
tined
toothed
unbated
lowering
papering