sad because one lacks friends or companions 孤寂的; 寂寞的: I live all alone but I never feel lonely. 我虽孑然一身, 但从不感孤寂. * a lonely-looking child 形单影只的孩子 * Living in a big city can be (ie make one feel) very lonely. 在大城市里生活还真很孤寂. * Hers is a lonely life. 她的生活很寂寞. 
[attrib 作定语] (of places) far from inhabited places; not often visited; remote （指地方）偏僻的, 人迹罕至的; 偏远的: Antarctica is the loneliest place on earth. 南极是地球上最偏远的地区. 
[attrib 作定语] without companions 孤单的; 无伴侣的: a lonely traveller 孤单的旅客. 
(idm 习语) plough a lonely furrow => plough v. =>Usage at alone 用法见alone. > loneliness n [U]: suffer from loneliness 备嚐孤寂之苦.# ,lonely `hearts people who are seeking friendship, esp with a view to marriage 徵友者（尤指物色佳偶者）: [attrib 作定语] a lonely hearts column, ie a section of a newspaper, etc containing messages from such people （报纸等的）徵友专栏.