Unlucky means having bad fortune. An unlucky break, unlucky in love, the unlucky one.
It says the outcome was chance rather than fault, which is why calling somebody unlucky is a kindness and calling a decision unlucky is an excuse. Unlucky in love is a fixed phrase. Note the superstitions: thirteen is the unlucky number in most of Europe, four in much of East Asia, and buildings skip those floors accordingly. Note also unluckily, which is heavier than unfortunately.
1adjectiveunluckyHaving bad fortune.
“He was unlucky to miss the train by just one minute.”
synonyms: unfortunate, ill-fated
unlucky is a quality of bad fortune.
Middle English
lukky
English
lucky
English, today
unlucky
From un- + lucky. lucky comes from Middle English lukky, equivalent to luck + -y. Cognate with Scots lucky (“lucky”), West Frisian lokkich (“lucky, fortunate”), Dutch gelukkig (“lucky, fortunate, happy”). Compare also Danish lykkelig (“happy”), Swedish lycklig (“happy, lucky”), German glücklich (“happy”), stq glukkelk (“happy”).
Etymology from Wiktionary, CC BY-SA