pickle vs gherkin

pickle and gherkin both are nouns.

Word	Noun	Adjective	Verb	Adverb
pickle	Yes	No	Yes	No
gherkin	Yes	No	No	No

As nouns, gherkin is a hyponym of pickle; that is, gherkin is a word with a more specific, narrower meaning than pickle:

Other hyponyms of pickle include caper, dill pickle, sweet pickle.

pickle (noun)	gherkin (noun)
vegetables (especially cucumbers) preserved in brine or vinegar	small prickly cucumber
informal terms for a difficult situation	any of various small cucumbers pickled whole

pickle (verb)	gherkin (verb)
preserve in a pickling liquid