coalesce

verb

1. To join into a single mass or whole.

   “The droplets coalesced into a puddle.”

   “[…] when a thing's own light and the light from something else coalescing into one on bright and smooth surfaces produce a form which yields a perception reversed from the way a thing normally looks.”

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.

   “It was not a wise thing to enter a close clique, my good madam, until you had examined both them and yourself, and considered how far you were likely to coalesce.”

   “We in the gay male community who are white […] will need to do conscious raising on racism with each other to effectively work with different racial groups. It follows that when attempting to coalesce with women that sexism conscious raising would need to occur.”

   “The result is that once again, as in 2016, Trump is likely to prevail because Republicans cannot coalesce around an alternative—even though a candidate who is experienced in government, solidly conservative, and acceptable to most factions of the party is right there in front of them.”

5. To convert a null value to a defined value.

   “You can improve the display by coalescing the ID columns. As I note in Chapter 9, the COALESCE expression takes on the value of the first non-null value in a list of values.”