辽 is a bound morpheme (b.f.) that appears in historical and geographical contexts. Its most common modern use is as the short name for Liaoning province (辽宁). It also refers to the Liao dynasty (907–1125), a Khitan-led dynasty in northern China. The classical meaning 'distant' survives in literary compounds like 辽远 ('far and wide'). You won't use 辽 as a standalone word in everyday speech — it always attaches to another character.