stimulant

Compared meaning: something that causes more activity or growth (noun).

比较义项：刺激、促进因素（名词）。

• stimulus

  A broad, often abstract cause that triggers activity, growth, or a response — money, a policy, an event; common in economics and general contexts, not a physical substance.

  泛指促使某事物产生活动、增长或反应的（往往是抽象的）因素——如资金、政策、事件；常用于经济学及一般语境，本身不是实际物质。

  The government announced a stimulus to help small businesses recover.

  政府宣布了一项刺激措施，以帮助小企业恢复。

• stimulant 本词

  A concrete substance, often a drug or chemical like caffeine, that physically speeds up the body or mind; something a person consumes or takes.

  指一种具体的物质，常是药物或化学品，例如咖啡因，能在生理上使身体或大脑更活跃；是人们摄入或服用的东西。

  Coffee is a common stimulant that helps people stay awake.

  咖啡是一种常见的兴奋剂，能帮助人们保持清醒。

Stimulus and stimulant both relate to causing more activity, but one is abstract, one physical. Stimulus is a broad cause that triggers activity or growth, like money or a policy. Stimulant is a concrete substance, a drug like caffeine, that quickens the body or mind.

两词都与“使更活跃”有关，但 stimulus 泛指任何促使事物产生活动或增长的因素，常用于经济、心理等抽象场合；stimulant 专指使身体或精神更活跃的实际物质（如药物、咖啡因）。这里不比较 stimulus 在生理学中“刺激信号”的专业义项，也不比较 stimulant 偶尔被泛化用来指“兴奋点、刺激物”的引申用法。