The excessive synchronization of the firing of neurons that leads to an epileptic seizure

(nonstandard) Alternative spelling of snugly

(logic) The second premise in a categorical syllogism, whose subject is the minor term and whose predicate is the middle term.

(quantum field theory) One of a set of three spacelike (and possibly also one timelike) four-dimensional vectors which are orthonormal within some inertial reference frame.