缘 is a bound form (b.f.) that always appears as part of a compound word. Its most culturally important meaning is 'fate, predestined connection' — central to the Chinese concept of 缘分 (fateful bond linking people or events) and 姻缘 (marriage fate). A second common sense is 'edge, fringe' as in 边缘 (edge, margin). A rare literary sense means 'along, follow' as in 缘路 (along the road). Because 缘 rarely stands alone, you must learn it through its compounds.