Sighingly is an adverb that describes the act of sighing or breathing out deeply and audibly as an expression of sadness or exhaustion. Some synonyms for sighingly include wistfully, longingly, mournfully, forlornly, regretfully, resignedly, wearily, and despondently. Each of these words conveys a sense of sadness or disappointment, but with slightly different nuances. For instance, wistfully suggests a sense of longing or nostalgia, while mournfully implies a feeling of grief or sadness. Similarly, resignedly conveys a sense of acceptance or acquiescence, while wearily suggests physical or emotional exhaustion. Whatever the context, these synonyms can help convey a sense of deep emotion and introspection to the reader.