Past tense of gallant (when used as a verb); acted with gallantry or courted someone in a showy manner.
From gallant (from Old French galant, from Frankish *wala meaning well) plus -ed for past tense. Less common than the adjective form.
You rarely hear 'gallanted' today because we don't really use 'gallant' as a verb anymore—it's a ghost word, a leftover from when courtly love and flowery romance language dominated the upper classes!
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