wistful
Feeling gently sad while wishing for something you can’t have.
Wistful describes a gentle sadness mixed with longing for something from the past or something you can't have. When you feel wistful, you're quietly yearning for something while accepting it's out of reach.
A grandmother might get a wistful look in her eyes when she remembers her own childhood summers. A student moving away might feel wistful thinking about friends they're leaving behind. You might feel wistful watching old home videos, remembering how much fun you had at a place you visited years ago.
The word captures that bittersweet feeling when memories make you both happy and a little sad at the same time. It's different from simply being sad: wistful includes a kind of tender appreciation for what was or what might have been. When someone gazes wistfully out a window on the last day of summer vacation, they're treasuring the memory of the fun they had while wishing it could continue.
You might recognize the related word wishful, which means full of hopeful desires. Wistful is gentler and more reflective, tinged with the understanding that what you long for may never come again.