use, send on a mission, order, messenger, envoy, ambassador, cause
使 centers on employing a person or thing to accomplish a purpose: using, ordering, or sending someone as a messenger or envoy. The 'cause' sense is a natural extension of making something happen through directed action.
使 combines 亻 (person) with 吏 (official), suggesting a person acting in an official capacity—using authority, giving orders, or being sent on a mission.
A person 亻 beside an official 吏: picture an official using a messenger to send orders. The messenger is employed to carry out the mission.
For シ, imagine the official handing a sheet of orders to the messenger: sheet -> シ, and the person uses it to send the envoy.
to use (a tool, method, etc.); to make use of; to put to use
use; application; employment; utilization; utilisation
errand; mission; going on an errand
angel
way of using (something); way to use; how to use; usage; use
embassy
use; exercise (of one's right, authority, power, etc.)
ambassador
mission; errand
using freely; making full use of; having a good command of
throwaway; disposable; single-use
proper use; using (different things) for different purposes
purpose; utility; objective
apostle; disciple
messenger; envoy; emissary
employee; servant
exploitation; overuse; abuse
labour and management; labor and management
special envoy
purpose for which money is spent; the way money is spent; how goods are used
envoy; ambassador; delegate; emissary; mission
envoy; diplomat below the rank of ambassador (e.g. deputy chief of mission, charge d'affaires); minister (of legation)
envoy to Tang China
errand; mission; going on an errand