look up any word, like ratchet:
 
1.
The maximum speed of a vehicle
That car will do 150mph at the top end
by BT4a November 04, 2011
 
2.
The northern (top) part of Australia's Northern Territory. Roughly that part which is north of Latitude 18 degrees South.
I'm a Ringer from the top end
by BT4a November 04, 2011
 
3.
Someone who is completely unaware of their stupidity, and also has similar meanings to words such as idiot, prat and fool.
Person 1 "You see that guy over there?"
Person 2 "Yeah"
Person 1 "He's a complete topend, can you see what he's trying to do."
by My Name Is Danny Scott March 12, 2008
 
4.
During or after sexual intercourse, while your "partner" is in the cowgirl/reverse cowgirl position you unceremoniously back hand them to the bedroom floor or parking lot, depending on where the coitus is occuring.

Second definition:
While having sex in a plane or on top of a high cliff vigorous thrusting causes your partner to go ass over tea kettle.

Topended:
Becca was glad she had gone for the gold health plan at work. Getting "topended" into a moped will surely require stitches'.

Topending:
Marsha was only a flight attendant and wasn't suppose to jump with the other skydivers. However, "topending" is what she received from a randy instructor. Thankfully her fall to earth was short and filled with orgasms.

Topend:
Not being one to consider the needs of others, Bob would often "topend" his partner as soon as he busted a nut.