n.1 the act or process of adhering.
2 the capacity of a substance to stick fast.
3 Med. an unnatural union of surfaces due to inflammation.
4 the maintenance of contact between the wheels of a vehicle and the road.
5 the giving of support or allegiance.
Usage:
More common in physical senses (e.g. the glue has good adhesion), with adherence used in abstract senses (e.g. adherence to principles).
Etymology: F adh{eacute}sion or L adhaesio (as ADHERE)