The highest gear that is available in a motor vehicle or car.

That serves as an addition

An addition. / A serving of drink used to top up an existing glass. / (insurance) An additional premium paid over the initial premium in order to increase benefit values.

having a high centre of gravity, and liable to topple / (of an organization) having an excessive number of administrators or managers

The upper deck of a double-decker bus.

A man's formal hat, with a tall cylindrical crown (often of silk). / (construction) A kind of steel batten.

to refill (or recharge) something / (UK) to refill the drink of (somebody) / (idiomatic) to extend the credit of something / to add to a number or amount, to bring something up to a certain level

(cricket) a type of ball, bowled by a leg spin bowler, that spins forward and, when bouncing off the pitch, bounces higher than expected and slows down

Used other than figuratively or idiomatically: see top, hand. / (cricket) The batsman's hand that is further up the handle; used for control rather than power.

(cricket) the batsmen who bat in the first few positions