dodder

n. [ Cf. Dan. dodder, Sw. dodra, G. dotter. ] (Bot.) A plant of the genus Cuscuta. It is a leafless parasitical vine with yellowish threadlike stems. It attaches itself to some other plant, as to flax, goldenrod, etc., and decaying at the root, is nourished by the plant that supports it. [ 1913 Webster ]

v. t. & i. [ Cf. AS. dyderian to deceive, delude, and E. didder, dudder. ] To shake, tremble, or totter. “The doddering mast.” Thomson. [ 1913 Webster ]

adj. 1. shaking as from old age.
Syn. -- doddery, shaking, tottering, tottery. [ WordNet 1.5 ]

2. mentally or physically infirm with age.
Syn. -- gaga, senile. [ WordNet 1.5 ]