nuclear

1. (by extension, figurative, of a solution or response) Involving an extreme course of action, or one with severe consequences.Examples: "nuclear option, nuclear solution"; "The states begging for aid get turned away; and sharp cuts in government employment, spending, and, eventually, pension payments are the only alternative future, beyond the nuclear solution of defaulting on our debt."; "The nuclear approach is the simpler of the two. When two constraints conflict, you can kill one of them."broadlyfigurativelynot-comparable

2. (biology) Pertaining to the nucleus of a cell.Examples: "However, the DNA in a bacterial cell is a single circular molecule and there is no separate nuclear compartment."not-comparable

3. (archaic) Pertaining to a centre around which something is developed or organised; central, pivotal.Examples: "Nuclear Polynesian languages include Hawaiian and Samoan."archaicnot-comparable