The Collaborative International Dictionary of English v.0.48:

Rambler \Ram"bler\ (r[a^]m"bl[~e]r), n.
   One who rambles; a rover; a wanderer.
   [1913 Webster]

WordNet (r) 3.0 (2006):

rambler
    n 1: a person who takes long walks in the country
    2: a person whose speech or writing is not well organized

Moby Thesaurus II by Grady Ward, 1.0:

32 Moby Thesaurus words for "rambler":
   Ahasuerus, Ancient Mariner, Argonaut, Flying Dutchman, Goliard,
   Odysseus, Oisin, Ossian, Ulysses, bird of passage, drifter,
   floater, gad, gadabout, go-about, itinerant, mover, peregrinator,
   peregrine, peripatetic, roamer, rolling stone, rover, runabout,
   straggler, stroller, strolling player, troubadour, visitant,
   wanderer, wandering minstrel, wandering scholar