本题考查词义的扩大。

Extension is a process by which a word which originally had a specialized meaning has now become generalized.

词义的扩大是一种最初具有专门意义的词现在被普遍化的过程。

A选项 disease (discomfort → illness) 词义由”不舒服“到”生病“，是词义的缩小。

B选项 liquor (liquid → alcoholic drink)词义由”液体“到”酒精饮料“，是词义的缩小。

C选项 wife (woman → a married woman)词义由”女性“到”结婚了的女性“，是词义的缩小。

D选项 allergic (too sensitive to medicine → averse to）词义由”对药物太敏感“到”嫌恶，讨厌“，是词义的扩大。

故选D。