Anglo-American term for a “wedgie” or “snuggy,” a word that was frequently used in the US in the 1970's and 1980’s to describe what happens when your undergarments make their way (intentionally or not) up into the crack of your buttocks. The term is derived from the act of flicking one’s knickers--the British word for women’s panties (i.e. long bloomers formerly worn as underwear by women and girls).
I hate wearing this polyester thong because it has given me a chronic case of flik-a-knicker—not too mention a raging case of jock-itch.
Byron’s incessant attempts at giving Gertrude a flicka-nicka were mildly amusing, but eventually became deeply boorish, particularly after he managed to tear the poor woman’s panties.