Cortaderia cor·ta·de·ria uncommon noun 1. tall ornamental grasses of South America and New Zealand and New Guinea: pampas grass Synonymsgenus Cortaderia Related words Word family Cortaderia richardiiCortaderia selloana Broader terms monocot genus Parts Gramineae Part of pampas grass WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.