13-Letter Words Containing: X,T,O

• manage in a makeshift way; do with whatever is at hand

• perform without preparation

• the mathematical process of finding the maximum value of a function

• the act of raising to the highest possible point or condition or position

• Any of various typically yellow-brown dinoflagellates (originally grouped as genus Zooxanthella) now assigned to the genera Symbiodinium and Amphidinium, notably found in coral reefs.