13-Letter Words Containing: A,L,L,O,N

• 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.

• in an unambiguous manner

• to an exceptional degree

• in a manner involving or inclined to conjecture and supposition

• with regard to taxonomy

• one part in a quadrillion equal parts

• the ordinal number of one quadrillion in counting order