catalyst
['kætəlɪst]
n. 触媒, 接触剂, 催剂, 刺激素, 促素

[] 催剂

[] 催剂

[医] 催剂

1. The offer of a new job provided just the catalyst she needed.
   份新正她需转契。
2. A substance, especially an enzyme, that initiates or modifies the rate of a chemical reaction in a living body; a biochemical catalyst.
   催剂活体应改体应速质，尤指酶；催剂
3. A process by which the hydrocarbon molecules of petroleum are broken into simpler molecules, as of gasoline or kerosene, by the addition of hydrogen under high pressure and in the presence of a catalyst.
   氢裂解将石油含氢裂更简单（象汽油油）程，裂程催剂压氢气件

catalyst
[ noun ]

1. (chemistry) a substance that initiates or accelerates a chemical reaction without itself being affected

<noun.substance>

2. something that causes an important event to happen

<noun.person>
the invasion acted as a catalyst to unite the country

catalyst \catalyst\ n.
1. (Chem.) a substance that initiates or accelerates a
chemical reaction without itself being affected; as,
thousands of enzymes serve in concert as calaysts to
produce the sequence of reactions we call ``life``; the
industrial production of cheap ammonia depended on finding
a good catalyst.
[WordNet 1.5]

2. something that serves as a precipitating occasion for an
event; as, the invasion acted as a catalyst to unite the
country.

Note: A catalyst is never the main cause of an event, but may
serve to hasten events for which the underlying causes
are present prior to the appearance or occurrence of
the catalyst.
[WordNet 1.5 +PJC]

3. something or someone that causes events to happen with
itself being changed.
[PJC]