Where does “Длъгополе” come from?

Длъгополе (Old Church Slavonic) comes from Old Church Slavonic длъгъ, from Proto-Slavic dъlgъ, from Proto-Indo-European *dʰlegʰ- — to owe, be indebted to.

Ancestry of “Длъгополе”, step by step

StepLanguageWordMeaning
1Old Church Slavonicдлъгъdebt; Alternative form of дльгъ
2Proto-Slavicdъlgъdebt
3Proto-Indo-European*dʰlegʰ-to owe, be indebted to
Every word from Proto-Indo-European *dʰlegʰ- →Every word from Proto-Slavic dъlgъ →Every word from Old Church Slavonic длъгъ →