| butterweed | (n) American ragwort with yellow flowers, Syn. ragwort, Senecio glabellus |
| butterweed | (n) any of several yellow-flowered plants of the genus Packera; often placed in genus Senecio |
| Butterweed | n. (Bot.) An annual composite plant of the Mississippi valley (Senecio lobatus). [ 1913 Webster ] |