Attractive enough to be worthy of romantic or sexual interest; appealing or likeable in appearance.
From 'fancy' (to find attractive) plus the suffix '-able' (capable of being). This is a British English term that emerged in modern usage to describe someone considered physically attractive or desirable.
This word is almost exclusively British slang—you won't hear it much in American English, which shows how different English-speaking countries develop their own unique words for the same concepts!
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