General synonyms:
* Winding
* Rambling
* Twisting
* Circuitous
* Wandering
* Digressing
* Ambling
More specific synonyms:
* For a path or river: Serpentine, sinuous, convoluted
* For a speech or writing: Digressive, rambling, discursive
* For a thought process: Unfocused, aimless, drifting
* For a person's movement: Strolling, sauntering, loafing
The best synonym for "meandering" will depend on the specific situation and the intended meaning.