Atop / Very close to, in any orientation or in time. / (idiomatic) In addition to something else. / (idiomatic) Fully informed about, and in control of, something; up to speed with.

On the highest point or surface. / (idiomatic) In a dominant position.

simple past tense and past participle of top

(informal) At the very most; as a maximum.

(slang, dated) Great; excellent.

plural of top

(darts) The uppermost field of a dartboard; the double-20 field

Third-person singular simple present indicative form of top

Also, additionally, moreover.

(physics) A quantum number of quarks and hadrons, determined by the number(s) of top quarks and antiquarks present. Symbol T.