Hi Vivien,
Three of my dictionaies have adopted the word gammer. One of them is AHD, in which it says "Gammer n. Chiefly British An elderly woman." And another dic says: "Gammer, a bantering word, refers to an elderly woman, especially one in country." This dic is English-Chinese one, however.
And I checked out Merriam-Webster Online Dictionary just now.
The result of the search:
Main Entry: gam·mer
Pronunciation: 'ga-m&r
Function: noun
Etymology: alteration of godmother
archaic : an old woman -- compare GAFFER
While the search results of AskOxford showed:
Sorry, there are no results for that search.
And, gammer was not found in the Cambridge Advanced Learner's Dictionary too.
But msn Encarta showes:
gam·mer (plural gam·mers)
noun
U.K. woman: a woman of advanced years, especially a woman from the country ( dated informal )
[Late 16th century. Origin uncertain: probably a contraction of godmother, with "ga-" by association with grandmother.]
Hmmm... interesting American dics.