The word 'lonely' is correct and usable in written English. It is an adjective that is used to describe feeling isolated and without companionship. Example sentence: She felt so lonely when she moved to a new city without any friends.
She was popular at school and had a noted instinct for caring, going out of her way to play with Michael, the neighbour with Down's syndrome, and paying regular visits to a lonely old man down the road known as Mr Partridge.
So far, it has been a pretty lonely fight.
Q: We were scathing about the BBC's decision to buy Lonely Planet.
And then Ray Davies talked about being lonely, and taxi lights shining bright in the busy city, and it made me even more apprehensive about this dizzy, busy place.
Middleton was credited with helping to persuade William not to drop out of university at the end of his lonely first term and to switch courses to read geography.
Snow, in this poem, is merciless and deadly: the lonely Lucy Gray, who wanders out into an unexpected blizzard, gets lost and is never seen again.
Even as a world's lonely eyes turn to Zurich, the unstoppable force of the Rumour Mill ploughs on, like a massive nonsense combine harvester, churning up everything in its path and making us all ponder what exactly it is we're doing here.
Ludwig does not simply clarify my doubts with English writing, it enlightens my writing with new possibilities
Simone Ivan Conte
Software Engineer at Adobe, UK