The Collaborative International Dictionary of English v.0.48:
doddering \doddering\ 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]WordNet (r) 3.0 (2006):
doddering adj 1: mentally or physically infirm with age; "his mother was doddering and frail" [syn: doddering, doddery, gaga, senile]