n.1 a clump of grass etc.
2 (in full tussock moth) any moth of the genus Orgyia etc., with tufted larvae.
Phrases and idioms:
tussock grass grass growing in tussocks, esp. Poa flabellata from Patagonia etc.
Derivatives:
tussocky adj.
Etymology: 16th c.: perh. alt. f. dial. tusk tuft