The zeugma and the pun

There are special SDs which make a word materialize distinct dictionary meanings. They are zeugma and the pun. Zeugma is the use of a word in the same grammatical but different semantic relations to two adjacent words in the context, the semantic relations being on the one hand literal, and on the other, transferred. e. g. Dora, plunging at once into privileged intimacy and into the middle of the room.
Zeugma is a strong and effective device to maintain the purity of the primary meaning when two meanings clash. The pun is another S.D. based on the interaction of two wellknown meanings of a word or a phrase. It is difficult to draw a hard and fast distinction between zeugma and pun. The only reliable distinguishing feature is a structural one: zeugma is the realization of two meanings with the help of a verb which is made to refer to different subjects or objects ( direct and indirect). The pun is more independent. Like any S.D. it must depend on a context. But the context may be of a more expanded character, sometimes even as large as a whole work of emotive prose.
e.g.- Did you miss my lecture ?
- Not at all.
Pun seems to be more varied and resembles zeugma in its humourous effect only.