Noun

1. A force that moves something along
2. The gradual departure from an intended course due to external influences (as a ship or plane)
3. A process of linguistic change over a period of time
4. A large mass of material that is heaped up by the wind or by water currents
5. A general tendency to change (as of opinion)
6. The pervading meaning or tenor
7. A horizontal (or nearly horizontal) passageway in a mine

Verb

1. Be in motion due to some air or water current
2. Wander from a direct course or at random
3. Move about aimlessly or without any destination, often in search of food or employment
4. Vary or move from a fixed point or course
5. Live unhurriedly, irresponsibly, or freely
6. Move in an unhurried fashion
7. Cause to be carried by a current
8. Drive slowly and far afield for grazing
9. Be subject to fluctuation
10. Be piled up in banks or heaps by the force of wind or a current