Examples from literature

• Also, there were comings and goings, and the erstwhile placid atmosphere of the cabin was vexed with strange perturbations and unrest. 
• Besides, he sought only the obscure hotels, where he was not likely to meet any of his erstwhile fellow passengers. 
• In the first place, one of our erstwhile opponents is fighting against a much stronger enemy. 
• The erstwhile amorous fiancée, who could hardly wait until marriage to test her lover, became now the wife and mother who hardly wished to be touched by her husband. 
• This ghostly encroachment on our erstwhile quiet domain has had more than one inconvenient result.