1.
gentle, gradual
Describes a slope, curve, change, or pace that is not steep or abrupt but proceeds slowly and smoothly.
2.
loose, relaxed, not tight
Describes something that is not tightly fitted, constrained, or strict. Can refer to clothing, rules, or atmosphere.
Usage
A na-adjective (緩やかな + noun, 緩やかに + verb). Often used in news and economic reporting for gradual changes. Sense 2 can describe both physical looseness and abstract flexibility.