'Rockweed' definitions:
Definition of 'rockweed'
(from WordNet)
noun
Coarse brown seaweed growing on rocks exposed at low tide
Definition of 'Rockweed'
From: GCIDE
- Rockweed \Rock"weed`\, n. (Bot.) Any coarse seaweed growing on sea-washed rocks, especially Fucus. [1913 Webster]