SPINIEST
SPINY
barbed, barbellate, briary, briery, bristled, bristly, burred, burry, prickly, setose, setaceous, spiny, thorny
(adjective) having or covered with protective barbs or quills or spines or thorns or setae etc.; “a horse with a short bristly mane”; “bristly shrubs”; “burred fruits”; “setaceous whiskers”
spinous, spiny
(adjective) having spines; “the dorsal fin is spinous”
Source: WordNet® 3.1
Adjective
spiniest
superlative form of spiny: most spiny
Source: Wiktionary
SPINY
Spin"y, a. Etym: [From Spine.]
1. Full of spines; thorny; as, a spiny tree.
2. Like a spine in shape; slender. "Spiny grasshoppers sit chirping."
Chapman.
3. Fig.: Abounding with difficulties or annoyances.
The spiny deserts of scholastic philosophy. Bp. Warburton.
Spiny lobster. (Zoöl.) Same as Rock lobster, under Rock. See also
Lobster.
Spin"y, n.
Definition: See Spinny.
Source: Webster’s Unabridged Dictionary 1913 Edition