Mourning is an emotional response to the loss of a loved one or something that has been cherished. ACHE and LAMENT are two words that can be used to describe the feeling of mourning. ACHE is a four-letter word that means to feel physical or emotional pain, while LAMENT is a six-letter word that means to express grief or sorrow. Together, these two words can be used to describe the feeling of mourning for a lost loved one or something that has been cherished.