Both cuddling and snuggling will give you a jolt of the "love hormone" oxytocin, says research from the University of California, San Diego. Certainly, "snuggle" and "cuddle" have the same meaning and can be used interchangeably. Still, each word carries individual connotations that may influence how you use it.
The word "cuddle" is listed as a definition of snuggle. Both words are transitive or intransitive verbs, meaning you may use them with or without direct objects. They describe an action involving pressing, drawing or lying close with tenderness, for comfort or warmth or from affection. Snuggling and cuddling occur most often in bed or on any kind of seating but are not limited to these locations.
Modern parlance often uses the two words without distinction. Still, while snuggling connotes a burrowing action, cuddling connotes holding, as in holding another person. The addition of the term "fondle" under cuddle’s definition also suggests that cuddling involves more handling. In contrast, the snuggle definition implies less manual movement or action.
You may think of cuddling as an action performed with children or pets, and snuggling as between romantic partners. However, the use relating to the lying closely that occurs after sexual intimacy is often referred to as cuddling, not snuggling.
The addition of "up", as in "cuddle up" or "snuggle up," is idiomatic but offers the nuance of a more protracted period of the activity.
Cuddle is the older word, dating back to 1510 to 1520, likely derived from Middle or Old English words that meant intimate, affectionate or to make friends with. It is also linked to the Provincial English "crewdle" or "croodle," which meant to crouch or crowd together, to cower, and also to feel cold. Snuggle was first used in 1680 to 1690 and is derived from the word "snug."
Synonyms for both words include bundle, caress, clasp, curl up, enfold, embrace, huddle, snuzzle, spoon, nestle and snoozle. Antonyms include push away, stay away and separate.