Coalesce

Verb

1. To join into a single mass or whole.

   "The droplets coalesced into a puddle."

2. To form from different pieces or elements.

   "The puddle coalesced from the droplets as they ran together."

3. To bond pieces of metal into a continuous whole by liquefying parts of each piece, bringing the liquids into contact, and allowing the combined liquid to solidify.
4. To merge, to intermingle freely.
5. To convert a null value to a defined value.