a.

1. 弱的，虚弱的；衰弱的
   She is still weak after her long illness.

   久病之后她仍很虚弱。

2. 软弱的，懦弱的；优柔寡断的
   He is a man of weak character.

   他这个人性格软弱。

3. 淡的；稀薄的；无味的
4. （能力等）弱的，差的[（+at/in）]
   He was weak in mathematics, but good at English.

   他数学差，但英语好。

5. （论据等）不充分的，无说服力的
   The evidence he produced was very weak.

   他拿出的证据很不充分。

6. 【语】弱变化的；不重读的[Z]
7. （价格）疲软的

adj.

1. lacking physical strength and energy.
2. liable to break or give way under pressure.
   ▸not convincing or forceful.
   ▸not secure, stable, or firmly established.
   ▸(of prices or a market) having a downward tendency.
3. lacking power, influence, or ability.
   ▸lacking intensity.
   ▸(of a liquid or solution) heavily diluted.
   ▸(of features) not strongly marked.
   ▸(of a syllable) unstressed.
4. Grammar  denoting a class of verbs in Germanic languages that form the past tense and past participle by addition of a suffix (in English, typically -ed).