Interception route is one of the three following routes:
The rainwater may run along the leaves and branches to the stem of the plant to reach the ground surface. This part is called stemflow.
Interception Loss :
The intercepted precipitation may be hold by the vegetation as surface storage and returned to the atmosphere by evaporation, this is termed as interception loss.
The intercepted precipitation hold by the vegetation can drip off the plant leaves to join the ground surface or the surface flow, this is known as throughfall.
Reference : Engineering hydrology by K. Subramanya